WORTH 40 POINTS HELLPPPP
What class of element is Astatine (At)?

Answers

Answer 1

Answer:

halogen.

nonmetal.

Explanation:


Related Questions

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.

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.

Which of the following contains a polyatomic ion?

sodium iodide

carbon monoxide

Iron II oxide

ammonium chloride

Answers

Answer:

i think its oxide not too sure

Answer:  

 Its should be ammonium chloride.

A picture to help you with another question like this

Which statement about Niels Bohr's atomic model is true?
O Higher orbits have lower energies.
O Each orbit has a specific energy level.
O Electrons can exist in any energy level.
O Orbits close to the nucleus have no energy.

Answers

Answer:

O Each orbit has a specific energy level.

Explanation:

Neils Bohr put forward his own model of the atom based on the quantum mechanics originally developed by Planck.

He assumed the Rutherford's model and suggested that the extranuclear part consists of electrons in specific spherical orbits around the nucleus.

The orbits/energy level are the permissible through which the electrons can move through.

His concept is based the concept that the electron can move round the nucleus in certain permissible orbitss

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:

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.

7. Use the concepts of relative abundance and relative weight to explain why carbon has an atomic mass of 12.011 amu when there are three isotopes of carbon weighing 12 amu, 13 amu and 14 amu. Why is the atomic mass not 13?

Answers

The  uncertainties  of  the  delta  measurements  and  the  uncertainty  of  the  atomic  weight  derivedfrom  the  best  measurement  of  isotopic  abundances  constrain  the  number  of  significant  figures  in  theatomic-weight values of the upper and lower bounds. For carbon, the fifth digit after the decimal pointis uncertain because of the uncertainty value of 0.000 027. Therefore, the number of significant digitsin the atomic-weight value is reduced to four figures after the decimal point. The Commission may rec-ommend  additional  conservatism  and  reduce  the  number  of  significant  figures  further.  For  the  lowerbound of carbon, 12.009 635 is truncated to 12.0096. For an upper bound, the trailing digit is increasedto ensure the atomic-weight interval encompasses the atomic-weight values of all normal materials. Inthe case of carbon, the upper bound is adjusted from 12.011 532 to 12.0116 to express four digits afterthe decimal point. The lower and upper bounds are evaluated so that the number of significant digits ineach  is  identical.  If  a  value  ends  with  a  zero,  it  may  need  to  be  included  in  the  value  to  express  therequired number of digits. The following are examples of lower and upper atomic-weight bounds foroxygen that could be published by the Commission in its various tables.

---------------------------

Extracted from" Atomic weights of the elements 2009 (IUPAC Technical Report)"

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.  

Learn More:https://brainly.com/question/25758173

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.

The balanced equation for the production of sugars by photosynthesis is shown below.
This equation demonstrates the law of conservation of mass because
A.
there are more oxygen atoms on the right side of the equation than on the left.
B.
there is the same number of compounds on the right side of the equation as the left.
C.
there is the same number of each type of atom on the right side of the equation as the left.
D.
the sugar molecule on the right has the same mass as the carbon dioxide molecules on the left.

Answers

Answer:

Black

Explanation:

Answer:

the answer is

-there is the same number of each type of atom on the right side of the equation as the left.

Explanation:

i have study island too :')

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

What role do wolves play in the tundra?

Answers

Predator? Not sure if that’s what your looking for.

Answer:

predator

Explanation:

Wolves, arctic foxes, and snowy owls are predators in the tundra.

an unknown substance has a mass of 57.4 g and occupies a volume of 34.3 ml. what is the density in g/ml?

Answers

Answer: 1.67

D=M/V

(D=57.4/34.3)= 1.67

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:

Suppose two students grab an end of a rope. Both shake a rope once in a upward direction to create crests traveling at each other. What would you see when crests meet? What type of interference does this show?

Answers

Answer:

This creates destructive interference.

Explanation:

When the two ends meet they will cancel each other out.

Both students are shaking the rope in the upward direction. Hence their crest will meet up and form the constructive  interference pattern. The intensity of the increases.

What is constructive interference ?

When two waves moves in phase, their crest or troughs add up and the amplitude of the wave increases. This phenomenon is called constructive interference.

If the two waves are passing out of phase to each other then they undergo destructive interference. The amplitude of the destructive interference pattern reduces from their initial values.

Here, both students are shaking the rope in the upward direction. Thus, they are in moving in phase. Hence their crest will meet up and form the constructive  interference pattern. The intensity of the increases.

Find more on interference?

https://brainly.com/question/16098226

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PLZ HELP ASAP WILL GIVE BRAINLIST

2AlCl3 + 2Al + 3Cl2
If 20.0 g of aluminum chloride are decomposed, how many molecules of chlorine gas are produced?
A )6.63 x 1022 molecules CI
B )2.70 x 1023 molecules Cl2
C )1.35 x 1023 molecules Cl2
D )9.42 x 1023 molecules Cl2

Answers

Explanation:

Molar mass of AlCl3 = 133.34g/mol

Moles of AlCl3 used

= 20.0g / (133.34g/mol) = 0.150mol

Mole Ratio of AlCl3 to Cl2 = 2 : 3,

Moles of Cl2 produced

= 0.150mol * (3/2) = 0.225mol

We know that 1 mole of any gas has

6.023 * 10²³ molecules.

Hence, number of molecules in Cl2

= 0.225mol * (6.023 * 10²³/mol)

= 1.35 * 10²³ molecules. (C)

which of these is an example of the climate of a region?
A. Dry
B. Foggy
C. Overcast
D. Sunny​

Answers

its dry i think

Explanation:

it might be dry

If the flour mixture is then taken and put into the oven for about 20 minutes, it turns into something very tasty. What kind of change has happened now?

Answers

Answer:

physical change

Explanation:

i got the same question sorry for the late response but that's the answer good luck

How do atoms in molecules bond?
plz answer I will give brainliest

Answers

Answer:

Via covalent bonds

Explanation:

Atoms in molecules are bonded together via covalent bonds. Covalent bonds are bonds that are formed by sharing of the valence electrons between two atoms.

The atoms can be of the same kind or of different kinds.

In most molecules, the two atoms are connected by sharing of their valence electrons. This way, each atom can attain stability by becoming isoelectric with the nearest noble gas. Some molecules are monoatomic, some are polyatomic.

How much heat must be used to raise the
temperature of 180. g water from 19° C to 96°C?
The specific heat of water is 4.18 J/gºC.

Answers

Answer:

Q =  57934.8 J

Explanation:

Given data:

Mass of water = 180.0 g

Initial temperature = 19°C

Fina temperature = 96°C

Specific heat capacity of water = 4.18 J/g.°C

Heat absorbed = ?

Solution:

Formula:

Q = m.c. ΔT

Q = amount of heat absorbed or released

m = mass of given substance

c = specific heat capacity of substance

ΔT = change in temperature

ΔT = 96°C - 19°C

ΔT = 77°C

Q = 180.0 g×4.18 J/g.°C×77°C

Q =  57934.8 J

which would be a stronger acid H3PO4 or H3PO2​

Answers

Answer:

h3po2

Explanation:

Answer:

i think it is H3PO4

Explanation:

A chemist is studying the rate of the Haber synthesis: N2 + 3H2 2NH3

Starting with a closed reactor containing 1.25 mol/L of N2 and 0.50 mol/L of H2, the chemist finds that the H2 concentration has fallen to 0.25 mol/L in 44 seconds.What is the N2 concentration after 44 seconds?

Answers

Answer:

1.17 M

Explanation:

Step 1: Write the balanced equation

N₂ + 3 H₂ ⇒ 2 NH₃

Step 2: Calculate the rate of disappearance of H₂

We will use the following expression.

rH₂ = - Δ[H₂]/t = - (0.25 M - 0.50 M)/44 s = 0.0057 M/s

Step 3: Calculate the rate of disappearance of N₂

The molar ratio of N₂ to H₂ is 1:3.

0.0057 mol H₂/L.s × 1 mol N₂/3 mol H₂ = 0.0019 mol N₂/L.s

Step 4: Calculate the final concentration of N₂

We will use the following expression.

[N₂] = [N₂]₀ - rN₂ × t

[N₂] = 1.25 mol/L - 0.0019 mol/L.s × 44 s

[N₂] = 1.17 M

The total thermal energy of a system depends jointly on the temperature, total number of in the system _______________, and the _______________of the material. *


1. Molecules/State

2. Molecules/Heat

3. Matter/Heat

4. Atoms/State

Answers

Answer:

Molecules/State

Explanation:

We know from the kinetic molecular theory that matter is made up of molecules. These molecules are in constant motion at various velocities and energies.

The total thermal energy refers to the total kinetic energies of these particles. It depends on the temperature of the system, the energies of the molecules present in the material and the arrangement of the object's molecules (states of matter).

Which statement correctly describes ionic bonds? Multiple Choice An ionic bond only forms between two atoms of the same element. Ionic bonds usually form between electrically neutral, stable atoms. An ionic bond is the electrostatic force that holds ions together when they form bonds. All of the answer choices are correct.

Answers

Answer:

An ionic bond is the electrostatic force that holds ions together when they form bonds

Explanation:

An ionic bond is formed when a metal looses electron(s) to a non metal leading to the formation of a positive ion and a negative ion.

An ionic compound is actually an ion pair, the ions are held together by strong electrostatic forces.

This strong electrostatic force that holds the ion pair together in ionic compounds is what we commonly call the IONIC BOND.  

Answer:

An ionic bond is the electrostatic force that holds ions together when they form bonds

Explanation:

I took this test and it was the correct answer :)

A radioactive substance has a half-life of 5 million years. What is the age of a rock in which 25% of the original radioactive atoms remain

Answers

Answer:

d. 10 million years

Explanation:

These are the options for the question

Choose one answer.

a. 2.5 million years

b. 5 million years

c. 15 million years

d. 10 million years

✓half-life of the radioactive substance= 5 million years

✓ Then for every 5 million years, original radioactive given (100%) percentage is reduced by factor of 1/2.

✓ 1st 5 million year; After the first 5 million years, the original radioactive is reduced as;

(100%) × 1/2 = 50% remains

✓2nd 5 million year: At 10 millions year, the 50% remaining radioactive is reduced by factor of 1/2

(50%) × 1/2 = 25% remains

Hence, at At 10 millions years 25% of the original radioactive atoms remain

.

Answer:

10 million years

Set Grouper to 70%. How do you think this level of fishing will affect the populations of the other fish in the simulated reef? Explain your reasoning.

Answers

Answer:

Greatly affect.

Explanation:

This level of fishing will greatly affect the populations of the other fish in the simulated reef because overfishing disturbs the equilibrium in the marine ecosystem. One fish is a food of another fish or the big fish act as a controller which controls the population of other small fishes and in that way the ecosystem is present in equilibrium state so overfishing will greatly affect the marine ecosystem.

ANSWER QUICK !!!
How many grams of hydrogen gas will be produced if you start with 15.0 grams of zinc and an excess amount of HCI?

balanced equation:
Zn + 2HCI = ZnCl2 + H2

Answers

Answer:

0.48g

Explanation:

Given parameters:

Mass of zinc  = 15g

Unknown:

Mass of hydrogen gas = ?

Solution:

To solve this problem, we need to state the balanced reaction expression first;

          Zn   +   2HCl   →   ZnCl₂    +   H₂

Find the number of moles of Zn;

    Number of moles  = [tex]\frac{mass}{molar mass}[/tex]    = [tex]\frac{15}{63.4}[/tex]    = 0.24mol

From the balanced reaction expression;

             1 mole of Zn will produce 1 mole of H₂  

            0.24mole of Zn will produce 0.24mole of hydrogen gas

Mass of hydrogen gas  = number of moles x molar mass

                                      = 0.24 x (2 x 1)

                                      = 0.48g

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 %

Which rule states that cracks on glass tend to form at a certain angle on the opposite side of the polnt of Impact?
The
rule states that cracks tend to form at a (n)
angle on the opposite side from the point of Impact.

Answers

Answer:

The 3R rule states that cracks tend to form at a (n) right angle on the opposite side from the point of impact.

Explanation:

A state of matter where the particles that make up a substance start to break apart

Answers

Answer:

Liquid

Explanation:

Other Questions
PLEASE HELPP ASAPPLEASE HELPP ASAP Will mark brainliest! A retailer marks up the price of a coffee mug from $6.25 to $8.77. By what percent did the price increase? Round totwo decimal placesa 28.73%b 39.68%c 40.32%d 45.97% A circle fits in a square with sides of 12 inches. What is the approximate area of the shaded region between the square and the circle? (Use 3.14 for Pi and round to the nearest whole number.)A. 31 in squaredB. 69 in squaredC. 106 in squaredD. 125 in squared I need help -Anwser I only have 10 minutes left Find the vertex of the parabola defined by the following equation. 3x^2-12x+11 In your own words, give a conclusion (small paragraph) on what you think about: why is technology important nowadays?Briefly in your own words write a paragraph explaining in detail in your opinion.If anyone can help I will really appreciate it a ton.Please provide as much as you know. What is the equation of a line that is perpendicular to a line with a slope of 2 and passesthrough the point (-2, 0)? Al Gore wanted a vote recount in four Florida countiesVolusia, Palm Beach, Broward, and Miami-Dade. What did these counties have in common?Map of the state of Florida showing the election results for each county. In the counties shaded red, Bush received most of the votes. In the counties shaded blue, Gore received most of the votes. In the northwest area of the state, the counties are primarily shaded red, with a few shaded blue near the state capital. In the northeast region of the state, most counties are shaded red. In central Florida, there is a mix of red and blue shaded counties. In the southwest region of the state most counties are shaded red. In the southeast region of the state, most counties are shaded blue. 2011 FLVS The counties had less than 20 percent of votes for the Democratic Party. The counties had less than 20 percent of votes for the Republican Party. The counties had high populations and more voters that chose Gore. The counties had low populations and more voters that chose Bush. Find the perimeter of this semi-circle with radius, r = 26cm.Give your answer as an expression in terms of ? What are the three main parts of an atom and what are their charges?Where are the electrons found in an atom? Question 3True or False. You must convert grams to moles to do stoichiometry.TrueDFalse Complete el parrafo con la forma correcta de los verbos entre parentesis en el preterite o el imperfect.Mientras ella ___ (dormir), los osos ___ (regresar) a la casa. ___ (descubrir) que alguien habia entrado en la casa. ___ (buscar) por toda la casa y ___ (encontrar) a Guerita. Los osos la ___ (comer), pero su carne ___ (ser) pudrida y los osos ___ (ponerse) enfermos. La casa no ___ (tener) bano, porque los osos siempre ___ (hacer) popo en el bosque. Los pobres osos ya no ___ (poder) comer carne de hamano porque ellos ___ (tener) malas memorias de lo que les ___ (pasar) cuando ellos ___ (comer) a Guerita. A baby weighing 10kg needs 100 ml of fluid per kg in a 24-hour period.Over two days, the child should have:A) 1000 mlB) 2000 mlC) 4800 mlD) 2400 ml why must we remember the Holocaust The image depicts new modes of manufacturing during the Industrial Revolution in Europe between 1750 and 1900. Which ofthese would have been a direct effect of this time period in Europe?))A)The demand for raw materials increased dramatically in Europe,B)Slavery increased in Europe as the demand for labor in factories increased.C)European technologies diffused to South Asia, making the region a globalpower.D)The world's economy became less global as countries grew more self-sufficient Which issue lead to Texas seceding from the union?the reservation system slaverywar with Mexico corruption Unit 8 homework 2 special right triangles Why did President Jackson believe nullification crisis wouldthreaten the stability of the nation? Please help! Geometry: Simplify the expression.- 2.6f +0.2f - 15 - 3i need help with this, anyone?