What is the oxidation number of calcium

Answers

Answer 1

Answer:

0 for the elemental form, +2 in its compounds.


Related Questions

What is an ecosystem? ?

Answers

Answer:

An ecosystem is a community or group of living organisms that live in and interact with each other in a specific environment.

Explanation:

That's the most straight forward explanation I could come up with

PLS HELLPPPP
Which of the following objects would have the greatest gravitational attraction between them if they were set 3.0 km apart?
A .20kg object and a 200kg object
A 10kg object and a 100kg object
A 30kg object and a 200,000kg object
A 400,000 kg object and a 100,000,000kg object

Answers

Answer:

A 400,000 kg object and a 100,000,000kg object

Explanation:

The objects with the most mass between them will have the greatest gravitational attraction.

This is why the last option is the right choice.

The reason for this is based on the Newton's law of universal gravitation which states that:

 "the gravitational force of attraction between two bodies is directly proportional to the product of their masses and inversely proportional to the square of the distance between them".

So, the more the mass, the greater the gravitational attraction between two bodies.

Which statement is always true about conversation of matter?
The mass of a system does not change during a chemical reaction
If a solid forms the mass of a system increases
If a gas forms the mass of a system decreases
The mass of a system changes when a substance changes from liquid to gas, but it does not change in a chemical reaction

Answers

Answer:

The mass of a system does not change during a chemical reaction

Explanation:

Correct Answers

100 POINTS FOR BEST ANSWER! What is the difference between LDOF and SDOF

Answers

An SDOF system is one whose motion is governed by a single, second-order differential equation. Only two variables, position and velocity are needed to describe the trajectory of the system. Many structures can be idealized as single degree-of-freedom systems.

The LDAP Data Interchange Format is a standard plain text data interchange format for representing LDAP directory content and update requests. LDIF conveys directory content as a set of records, one record for each object.

The gas carbon dioxide is a pure substance. Which of the following is true about carbon dioxide? (5 points)

Select one:
a. Carbon and oxygen are chemically bonded in it.
b. Carbon and oxygen retain their original identity in it.
c. It can be separated into carbon and oxygen using physical methods.
d. The proportion of carbon and oxygen is different in different samples of the gas.

Answers

Answer:

Carbon and oxygen are chemically bonded in it.

Explanation:

The other answer choices do not apply for compounds, but rather for mixtures instead.

A force of 7 N acts on an object. The displacement is, say 8 m, in the direction of the force. Let us take it that the force acts on the object through the displacement. What is the work done in this case?

Answers

Answer:

56 J

Explanation:

Step 1: Given data

Force applied on the object (F): 7 NDisplacement of the object (d): 8 m

Step 2: Calculate the work (w) done on the object

We can find the work done on the object using the following expression.

w = F × d × cosθ

where

θ is the angle between F and d

Since F and d occur in the same direction, θ = 0° and cosθ = 1. Then,

w = F × d × 1

w = F × d

w = 7 N × 8 m = 56 J

a sample of fully saturated clay weighs 1350 g in its natural state and 975 g after drying. what is the natural water content of the soil

Answers

Answer:

The soil has a percentage of water by mass of 27.8 %.

Explanation:

Keeping in mind that

Mass of Clay = Mass of water + Mass of Dry Soil

we can calculate the mass of water:

1350 g = Mass of Water + 975 gMass of Water = 375 g

We can then calculate the mass percentage of water in the soil:

375 / 1350 * 100% = 27.8 %

What type of rock is limestone? Describe how a limestone rock is likely to change over a long period of time. Pls answer I will mark brainiest.

Answers

It is a sedentary rock. Limestone are usually affected by chemical weathering when rainwater (containing a weak carbonic acid) reacts with limestone. This causes the limestone to dissolve.
Question:

What type of rock is limestone? Describe how a limestone rock is likely to change over a long period of time. Pls answer I will mark brainiest.

Answer:Sedimentary Rock Limestone being a sedimentary rock would be converted to marble, a metamorphic rock if subjected to metamorphic conditions over an extensive period of time. Over a long period of time, we would take a look at the rock "limestone" through the rock cycle.

#CARRYONLEARNING #STUDYWELL

A catalyst decreases the activation energy of a particular exothermic reaction by 56 kJ/mol, to 35 kJ/mol. Assuming that the mechanism has only one step, and that the products are 78 kJ lower in energy than the reactants, sketch approximate energy-level diagrams for the catalyzed and uncatalyzed reactions. What is the activation energy for the uncatalyzed reverse reaction

Answers

Answer:

Activation energy for the uncatalyzed reverse reaction = 103 kJ/mol

Explanation:

Activation energy decreases from = 56 kj/mol to 35 kj/mol

products = 78 KJ lower in energy than reactants

Activation energy for the uncatalyzed reverse reaction = 103 kJ/mol

attached below are the sketches of approximate energy-level for both catalyzed and uncatalyzed reactions

PLEASE HELP BRAINLIEST AND 15 points.

1. Which substance is nonvolatile ?
(1.5 Points)
Substance B, boiling point of 105 °C
Substance C, boiling point of 25 °C
Substance A, boiling point of 75 °C
Substance d, boiling point of 45 °C

Answers

Answer:

Substance B, boiling point of 105 °C

Explanation:

Non volatile substances have high boiling points

Which element in group 17 has the highest ionization energy

Answers

Answer:

fluorine

Explanation:

it has the highest electronegativity in the group and in the periodic table

identified the nucleus that is found in an item that has a stable valance electron configuration

Answers

Answer:

Nucleus 3 i believe

A copper wire is 44.85 cm long and weighs 1.521 g. The density of copper is 8.933 g/cm3.

What is the radius of the wire in millimeters?
What is the diameter of the wire?

Answers

Answer:

i am so sorry

Explanation:

The density of copper is  If a sample 8.933 g/cm3. If copper has a volume of 12.993 cm^3. Then the mass will be 136.29 gram.

How can we calculate the mass from density and volume?

Density is defined as the mass per unit volume it means that mass present in 1 meter cube is called density. The S.I unit of density is kg/m^3 and in C.G.S it is gram/cm^3

So, In above question can understand that density, mass, and volume all are convert to each other it means that if we know any two variable then third one will be calculated easily.

Mathematically,

Formula for density will be as mentioned below:-

Density = Mass/Volume.

From above formula we can calculate mass which is as follows:-

Mass = Volume × Density.

S.I unit of mass is kilograms and C.G.S unit is gram.

So In above question

Density = 8.933 gram/cm^3

Volume = 12.993 cm^3

So from above formula

Mass = Density × volume

          = 10.49 × 12.993

          = 136.29 gram

          = 0.13629 kilogram

So Mass is equal to 136.29 gram or 0.136 kilograms.

Therefore,The density of copper is  If a sample 8.933 g/cm3. If copper has a volume of 12.993 cm^3. Then the mass will be 136.29 gram.

Learn more about density here:

https://brainly.com/question/15164682

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You can use solid, wedged, and dashed lines to better represent the 3D structure of molecules. The solid lines represent bonds in the plane of the paper, wedged lines represent a bond coming out of the plane, and the dashed line represents a bond going back behind the plane of the paper. Draw a representation of methane that better depicts its 3D structure.

Answers

Answer:

See explanation and image attached

Explanation:

Often times, there is a need for a three dimensional representation of a molecule on paper. These three dimensional representations give us an idea of what the molecule really looks like if we were to be looking at it physically.

In order to make a three dimensional representation, we use wedged and dashed bonds. The wedged bonds are coming out of the plane of the paper towards you while the dashed bonds are going into the plane of the paper away from you.

In the image attached, you will find the three dimensional representation of the methane molecule.

If it takes 38.70cm of 1.90M NaOH to neutralize 10.30cm of H2SO4 in a battery, what is the molarity of H2SO4?

Answers

Answer:

The molarity of the acid, H₂SO₄ is 3.57 M

Explanation:

We'll begin by writing the balanced equation for the reaction. This is illustrated below:

H₂SO₄ + 2NaOH —> Na₂SO₄ + 2H₂O

From the balanced equation above,

Mole ratio of the acid, H₂SO₄ (nₐ) = 1

Mole ratio of the base, NaOH (n₆) = 2

Finally, we shall determine the molarity of the acid, H₂SO₄. This can be obtained as follow:

Volume of base, NaOH (V₆) = 38.70 cm³

Molarity of base, NaOH (M₆) = 1.90M

Volume of acid, H₂SO₄ (Vₐ) = 10.30 cm³

Molarity of acid, H₂SO₄ (Mₐ) =?

MₐVₐ / M₆V₆ = nₐ/n₆

Mₐ × 10.3 / 1.9 × 38.70 = 1/2

Mₐ × 10.3 / 73.53 = 1/2

Cross multiply

Mₐ × 10.3 × 2 = 73.53 × 1

Mₐ × 20.6 = 73.53

Divide both side by 20.6

Mₐ = 73.53 / 20.6

Mₐ = 3.57 M

Thus, the molarity of the acid, H₂SO₄ is 3.57 M

When 70.4 g of benzamide (C7H7NO) are dissolved in 850. g of a certain mystery liquid X, the freezing point of the solution is 2.7 C lower than the freezing point of pure X. On the other hand, when 70.4 g of ammonium chloride (NH CI) are dissolved in the same mass of X, the freezing point of the solution is 9.9 °C lower than the freezing point of pure X.

Required:
Calculate the van't Hoff factor for ammonium chloride in X.

Answers

Answer:

1.62

Explanation:

From the given information:

number of moles of benzamide  [tex]=\dfrac{70.4 \ g}{121.14 \ g/mol}[/tex]

= 0.58 mole

The molality = [tex]\dfrac{mass \ of \ solute (i.e. \ benzamide )}{mass \ of \ solvent }[/tex]

[tex]= \dfrac{0.58 }{0.85 }[/tex]

= 0.6837

Using the formula:

[tex]\mathbf {dT = l \times k_f \times m}[/tex]

where;

dT = freezing point = 27

l = Van't Hoff factor = 1

kf = freezing constant of the solvent

2.7 °C = 1 × kf ×  0.6837 m

kf = 2.7 °C/ 0.6837m

kf = 3.949 °C/m

number of moles of NH4Cl = [tex]\dfrac{70.4 \ g}{53.491 \ g /mol}[/tex]

= 1.316 mol

The molality = [tex]\dfrac{1.316 \ mol}{0.85 \ kg}[/tex]

= 1.5484

Thus;

the above kf value is used in determining the  Van't Hoff factor for  NH4Cl

i.e.

9.9 = l × 3.949 × 1.5484 m

[tex]l = \dfrac{9.9}{3.949 \times 1.5484 \ m}[/tex]

l = 1.62

If you have 3.5 L of He to blow up balloons... at STP...

a) How many moles of He do you have?

b) How many grams of He do you have?

Answers

Answer:

B

Explanation:

Bond length is the distance between the centers of two bonded atoms. On the potential energy curve, the bond length is the internuclear distance between the two atoms when the potential energy of the system reaches its lowest value. Consider that the atomic radius (sometimes called the covalent or bonding atomic radius) of an element is defined as one-half the distance between the bonded atoms in a homonuclear diatomic molecule. Actual bond lengths in molecules are determined experimentally by such methods as X-ray diffraction and microwave spectroscopy. However, these atomic radii values can be used to give an estimate of the upper limit of bond length in other (heteronuclear) molecules. Given that the atomic radii of H and Br are 37.0 pm and 115 pm , respectively, predict the upper limit of the bond length of the HBr molecule.

Answers

Answer:

152 pm

Explanation:

According to the question, we can estimate the bond length from the given values of the atomic radii. This now is the upper limit of the bond length for the molecule.

Since we have that;

Atomic radius of H= 37.0 pm

Atomic radius of Br = 115.0 pm

Bond length = Atomic radius of H + Atomic radius of Br

Bond length = 37.0 pm + 115.0 pm

Bond length = 152 pm

Ammonium phosphate is an important ingredient in many solid fertilizers. it can be made by reacting aqueous phosphoric acid with liquid ammonia. calculate the moles of ammonium phosphate produced by the reaction of 0.085 mol of ammonia. be sure your answer has a unit symbol, if necessary, and round it to the correct number of significant digits.

Answers

Answer:

0.028 mole of ammonium phosphate, (NH₄)₃PO₄.

Explanation:

We'll begin by writing the balanced equation for the reaction. This is illustrated below:

H₃PO₄ + 3NH₃ —> (NH₄)₃PO₄

From the balanced equation above,

3 moles of NH₃ reacted to produce 1 mole of (NH₄)₃PO₄.

Finally, we shall determine the number of mole of (NH₄)₃PO₄ produced by the reaction of 0.085 mole of ammonia, NH₃. This can be obtained as follow:

From the balanced equation above,

3 moles of NH₃ reacted to produce 1 mole of (NH₄)₃PO₄.

Therefore, 0.085 mole of NH₃ will react to produce = (0.085 × 1)/3 = 0.028 mole of (NH₄)₃PO₄.

Thus, 0.028 mole of ammonium phosphate, (NH₄)₃PO₄ were obtained from the reaction.

Which factors directly affect the magnetic force produced by an electromagnet?

O number of turns in the wire, amount of current

O amount of current, type of force

O length of core, number of turns in the wire

O amount of current, length of core

Answers

It’s o amount of current,type of force
o mount of current type of force

GRADE 5 SCIENCE MYA-2020-2021
Testosters are testing the choict of light on a radiometer Team 1 finds that blue light makes the radiometer spin slower when a blue light is 35 centimeters (cm) away. To validate Team 1's test results, how must
Text with and that is 20 cm away
Test what that is 45 cm away
Test with a green light that is 40 cm away
Test with the light that is 35 cm away

Answers

Answer:

Test it with a blue light that is 45 cm away.

Explanation:

What is the mass of 3.00 -1023 particles of water? Water has a molar mass of 18.0 g/mol.
3.00 grams
18.0 grams
6.00 grams
9.00 grams

Answers

Answer:

bro

Explanation:

guhfuyfouyvyu

Answer:

9.00

Explanation:

I took the test and got it correct ...

You'll be given 100 points if you answer this question!!!!!!!!!!!!

3.
What do we call materials
that let heat pass through
them easily?
Thermal conductors
Thermal insulators
Transparent
4.
Which of these is a good
thermal conductor?
Plastic
Wood
Steel
5.
Which of these is a good
thermal insulator?
Steel
Iron
Polystyrene
6.
To save on heating bills, do
you think the roof of a
building should be lined with
a thermal conductor
a thermal insulator
nothing
7.
How does heat travel?
From cold things to hotter things
From hot things to colder things
Between things of the same temperature

Answers

Answer:conducts ,steel, polystyrene, thermal insulation

Explanation:

To solve the ultraviolet catastrophe, Planck applied quantization to: Select the correct answer below:
A. vibrational energies of atoms
B. orbital energies of electrons
C. kinetic energies of photons
D. temperature of the system

Answers

Answer:

Vibrational energies of atoms

Explanation:

Planck applied quantization to Vibrational energies of atoms because in Black body spectrum prediction a blackbody at equilibrium is expected to radiate energies at various Frequencies ( i.e. increase in radiated energy ∝ increase in frequency ) but towards the ultraviolet region of the spectrum the energy radiated begins to drop as frequency increases. The phenomenon of drop in energy with increase in frequency is termed Ultraviolet catastrophe. hence to solve this phenomenon Planck applied quantization to Vibrational energies of atoms

In the kinetic theory, the particles in a gas
A. move independently of each other.
B. have attractive and repulsive forces.
C. move slowly.
D. are relatively close together.

Answers

Answer:

Im pretty sure its B

Sorry if Im wrong

Explanation:

Have a wonderful day!!!<3

Answer:

The only answer that could apply to a gas is A

Explanation:

Why do organisms eat food? Be sure to explain your answer. ​

Answers

Answer:

Organisms need to take food to get energy and perform life processes. A living organism undergoes many life processes like nutrition, respiration, digestion, transportation, excretion, circulation of blood, and reproduction. To perform all these life processes the organism needs energy and nutrients.

Explanation:

nnastarannnn his idea

A certain substance X condenses at a temperature of 123.3°C . But if a 650. g sample of X's prepared with 24.6 g of urea ((NH2)2 CO) dissolved in it, the sample is found to have a condensation point of 124.3°C instead. Calculate the molal boiling point elevation constant Kb of X.

Answers

Answer:

1.6 °C.kg/mol

Explanation:

Step 1: Calculate the molality of urea

We will use the following expression.

m = mass(urea) / molar mass(urea) × kg solvent

m = 24.6 g / 60.06 g/mol × 0.650 kg

m = 0.630 mol/kg

Step 2: Calculate the boiling point elevation of X

The boiling point elevation is a colligative property that can be calculated using the following expression.

ΔTb = 124.3 °C - 123.3 °C = 1.0 °C

Step 3: Calculate the boiling point elevation constant

We will use the following expression.

ΔTb = Kb × m

Kb = ΔTb/m

Kb = 1.0 °C/(0.630 mol/kg) = 1.6 °C.kg/mol

Find the mass in grams of 1.38 moles of Sr

Answers

Answer:

116.78 grams.

Explanation:

1 mol of Strontium (Sr) = 87.62 grams

1.38 mol of Strontium = x

Cross Multiply

1 * x = 1.38 * 87.62

x = 116.78  grams

Which of the following has the largest atomic radius?​

Answers

I think it’s B
But I could be wrong

Hope it helps :)

Answer:

b

Explanation:

Which of the following is a list of the minimum amount of data needed for determining the molar enthalpy of solution of KCl(s) in pure H2O(1) ? (Assume that the KCl(aq) has the same specific heat capacity as pure water and that the initial temperatures of the KCl(s) and the water are the same.)
(A) Mass of KCl(s), initial temperature of the water, and final temperature of the solution
(B) Mass of H20, initial temperature of the water, and final temperature of the solution
(C) Mass of KCl(s), mass of H20, initial temperature of the water, and final temperature of the solution
(D) Mass of KCl(s), mass of H20, initial temperature of the water, final temperature of the solution, and atmospheric pressure

Answers

Answer:

 (C) Mass of KCl(s), mass of H20, initial temperature of the water, and final temperature of the solution

Explanation:

molar enthalpy of solution of KCl(s) is heat evolved or absorbed when one mole of KCl is dissolved in water to make pure solution . The heat evolved or absorbed can be calculated by the following relation.

Q = msΔt where m is mass of solution or water , s is specific heat and Δt is change in temperature of water .

So data required is mass of water or solution , initial and final temperature of solution , specific heat of water is known .

Now to know molar heat , we require mass of solute or KCl dissolved to know heat heat absorbed or evolved by dissolution of one mole of solute .

The correct option is option C.

To determine the molar enthalpy of the solution of [tex]Kcl(s)[/tex] is pure [tex]H_2O(l)[/tex]

We need to know that the,

grams of [tex]Kcl(s)[/tex]  grams of [tex]H_2O[/tex]  Initial temperature of [tex]H_2O[/tex]  The final temperature of the solution.  

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Find the product. Enter the product in simplest form. 8 x 1/3 = In this activity, you will record a short paragraph, in Spanish, describing your ideas for protecting the environment at home and at school using any audio recording software. Use the vocabulary about environmental protection and sustainability that you learned in the lesson. Submit the audio file to your teacher. Write a body paragraph for an explanatory essay that supports the claim and uses academic writing throughout. Your assignment should include the following elements: Evidence from "The Chrysanthemums" to support the claim you were given - The discount is $4.40 off for each mug. - The club is able to order 24 mugs if they choose this company The club has a budget of $120 for the mugs. There is a set-up fee for each order, but the company decides to waive the fee for the science club. What is the regular price per mug at this company? -5(-y+5)+ 5y=-5Solved by substitution The sum of two consecutive odd integers is 144. Which expression may be used to solve the problem? Consider a firm making production decisions in the short run. Select the statement(s) that must be correct. Choose one or more: A. Average total cost will always exceed average variable cost. B. Average total cost cannot decline as output increases, at any level of output. C. Average fixed cost cannot increase with output, at any level of output. D. Average variable cost is always above the average fixed cost. E. Average variable cost cannot decline with output, at any level of output. Mariah has a spinner that has 10 equal sections, each containing a different number from 1 to 10. Mariah determines about how many times the spinner will land on a number that is greater than 7 in 250 spins, and her work is shown below.P (number greater than 7) = StartFraction Number greater than 7 over Total number of sections EndFraction times number of spins = StartFraction 4 over 10 EndFraction (250) = 100.What mistake did Mariah make, if any? Mariah has the formula reversed; it should be the total number of sections over the numbers greater than 7.Mariah should have used a 3 in the numerator because there are 3 numbers greater than 7.Mariah should multiply by the number of sections in the spinner rather than the total number of spins.Mariah calculated the prediction correctly and did not make any mistakes. PLEASE HELP I NEED HELP WITH AN ALGEBRA 2 QUESTION ILL GIVE BRAINLEST Hey need this ASAP Ive work through almost just need this one _____refers to the "gap" between rich and poor that helped contribute tothe Great Depression." What causes the phases of the moon ? Show how to rewrite 1/5 with the denominator 10 Between the green skinned lime and the yellow skinned lime, which of these are more acidic. 12. Which of the following numbers is contained in the solution set of the inequality|-5x + 351 > 20? Choose the best answer.A beekeeper pays $30 to rent a booth at a farmers' market.She charges $5 for each jar of honey. The graph shows thissituation, which is modeled by the equation y = 5x - 30.Which of the following is true?A. The value of x can be negative.B. The value of y can be negative.C. The value of x can be fractional.D. The value of y cannot be zero.X pls helpppppppppp!!!!!! Which best describes a difference between enslaved people in cities and those on plantations in the 1800s?Enslaved people in cities were not considered to be property, while enslaved people on plantations were thought of as property.Enslaved people in cities often kept some of their wages, while enslaved people on plantations never received any wages.Enslaved people on plantations could learn a trade or a skill, while enslaved people in cities were thought of as unskilled labor.Enslaved people on plantations did less manual labor, while enslaved people in cities spent more hours doing backbreaking work. calculate ine gravitational potential energy of the ball using pe=mgh.(use g=9.8 n/kg)A 4.0-kilogram ball held 1.5 meters above the floor has ________ joules of potential energy He be having more drip thin connies