Which of the following represents an element ? H2O H2 NaCl CaCO3
Answer:
H₂
Explanation:
H₂ is hydrogen in its elemental form.
H₂O, NaCl, and CaCO₃ are all examples of elements added together to create compounds.
A test light with an electrical resistance of 9.00 S2 draws a current of 1.50 A when
it is connected to an electrical source. How much power does the light use?
Answer:
20.25 W
Explanation:
Applying,
P = I²R.................... Equation 1
Where P = Power, I = current drawn by the test light, R = Resistance of the test light
From the question,
Given: I = 1.5 A, R = 9.00 Ω
Substitute these values into equation 1
P = (1.5²)(9)
P = 2.25×9
P = 20.25 W
sources of magnesium to plants
How would the balloons interaction with each other change if the balloons were moved further apart? Explain.
Explanation:
It is known that like charges repel each other and unlike charges attract each other.
As the balloons are facing each other with like charges so they will repel each other. Hence, they will move apart.
But when balloons were moved further apart then interaction between them will decrease and then there will be no force of repulsion or force of attraction.
Write a nuclear equation for the beta decay of Promethium-165
Answer:
see your answer in pic
Explanation:
There can be emissions of radiations like gamma radiation. There can be emission of particles too like alpha particle. Therefore, the nuclear equation for the beta decay of Promethium-165 is
¹⁶⁵Pm[tex]\rightarrow[/tex]⁰e₋₁ + ₆₂Sm¹⁶⁵
What is nuclear decay?Nuclear decay is process in which the radioactive element releases particles or radiations. Alpha particles is ⁴₂He. Alpha particle is nothing but helium particle. The kinetics that is related to nuclear decay is of first order.
The nuclear equation for the beta decay of Promethium-165 is
¹⁶⁵Pm[tex]\rightarrow[/tex]⁰e₋₁ + ₆₂Sm¹⁶⁵
Beta decay of Promethium-165 is the emission of electron particle from the given isotope. the product is Samarium ₆₂Sm¹⁶⁵.
Therefore, the nuclear equation for the beta decay of Promethium-165 is
¹⁶⁵Pm[tex]\rightarrow[/tex]⁰e₋₁ + ₆₂Sm¹⁶⁵
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Aqueous solutions of a strong acid and a weak acid of equal concentrations are compared. Which of the following statements are true?
I. The strong acid reacts with a metal oxide but the weak acid does not
II. The weak acid is less disassociated than the strong acid
III. The strong acid has a greater conductivity that the weak acid.
Answer:
Explanation:
Which of these is true for natural selection but not artificial selection?
A.Humans choose specific organisms to reproduce.
B.Competition for resources determines reproductive success.
C.Unfavorable traits decrease in frequency in a population.
D.Genetic engineering introduces new traits into a population.
Answer:
B
Explanation:
The formula for calclum chloride Is CaCl2. Which argument best describes the type of chemical bond that was formed between the calcium and chlorine atoms? An lonic bond because calcium is sharing its electrons with the chlorine. A covalent bond because calclum is transferring its electrons to the chlorine. A covalent bond because calcium is sharing its electrons with the chlorine. An lonic bond because calcium is transferring Its electrons to the chlorine.
Answer:
An lonic bond because calcium is transferring Its electrons to the chlorine.
Explanation:
Metals usually form compounds with non-metals through ionic bonding.
Metals are electropositive elements which form ions by the loss of electrons, whereas non-metals are electronegative elements which form ions by the gain of electrons.
Compounds are formed when two or more elements combine together. The formation of compounds involves formation of bonds which may be either ionic or covalent bonds.
The type of bonding that exists between the a metallic calcium atoms and non-metallic chlorine atoms in calcium chloride, CaCl₂, is ionic bonding. In the process of formation of the compound, calcium atoms which have a valency of 2 readily donates their two valence electrons to chlorine atoms to form calcium ions, Ca²+. Each chlorine atoms having a valency of 1 accepts an electron to form chloride ions Cl-. Two chlorine atoms accept the two electrons donated by a calcium ion. Due to strong electrostatic forces of attraction between the calcium ion and the two chloride ions, the ionic compound CaCl₂ is formed.
Find the area of the sector with a central angel of 120 and a radius of 8 inshces. Leave in terms of pie
Answer:
A = 66.98 square in.
Explanation:
The Area of a sector is given by the formula
[tex]A = \frac{\theta}{360}\times \pi r^2[/tex]
here θ is the central angle and r is the radius
given that θ = 120° and radius = 8 inches
[tex]A = \frac{120}{360}\times3.14\times 8^2[/tex]
A = 66.98 square in.
Al2S3 + 6H20 + 2Al(OH)2 + 3H2S
How many TOTAL number mole to mole ratios will there be total?
Answer:
the correct answer is 23:19
What can a nation do to improve the exchange rate of its currency?
A.
try to improve its balance of trade
B.
try to decrease its trade surplus
C.
try to lower its gross domestic product (GDP)
D.
try to export less while importing more
Answer:
A
Explanation:
balance the trades and improving them
Answer:
A:try to improve it's balance of trade
Explanation:
Vhon Anadome
Atomic nucleus questions
Which of the following decay processes results in the largest change in mass of a nucleus?
Choose 1 answer:
А
Beta decay
Gamma decay
Neutron emission
D
Alpha decay
Answer:
d
Explanation:
HELP ASAAAAP 40 MINS LEFT AAA!
Geometric isomers have profound effects on the physical properties of compounds. Naturally occurring fatty acids generally adopt a cis geometry. What's one physical property affected by this geometry?
A)
Color
B)
Taste
C)
Smell
D)
Melting point
1. BaBr2(aq) + H2SO4(aq) →?
please balance the equation and predict the products
Answer:
BaBr2 (aq) + H2SO4 (aq) → BaSO4 (s) + 2 HBr (aq)
Explanation:
This is a precipitation reaction: BaSO4 is the formed precipitate.
Determine the volume of a helium balloon given the balloon was filled from a container 0.15L of gas at 2 atm if the new pressure is 0.97 atm. Assume constant temperature.
Answer:
The volume of the helium balloon is 0.306 L.
Explanation:
Boyle's law states that the volume occupied by a given gaseous mass at constant temperature is inversely proportional to pressure. That is, if the pressure increases, the volume decreases, while if the pressure decreases, the volume increases.
Mathematically, Boyle's law indicates that the product of pressure and volume always has the same value:
P*V= k
Assuming that you have a certain volume of gas V1 that is at a pressure P1 at the beginning, by varying the volume of gas to a new value V2, then the pressure will change to P2, and it will be fulfilled:
P1*V1= P2*V2
In this case:
P1= 2 atmV1= 0.15 LP2= 0.97 atmV2= ?Replacing:
2 atm* 0.15 L= 0.97 atm* V2
Solving:
[tex]V2= \frac{2 atm* 0.15 L}{0.97 atm}[/tex]
V2= 0.306 L
The volume of the helium balloon is 0.306 L.
Calculate weight of anhydrous compound from remains upon dehydration of 2g copper sulphate pentahydrate
Answer:
1.28 g
Explanation:
Mass of anhydrous compound/molar mass of anhydrous compound = mass of hydrated compound/ molar mass of hydrated compound
Mass of anhydrous compound = ?
Mass of hydrated compound = 2g
Molar mass of anhydrous compound= 160 g/mol
Molar mass of hydrated compound = 250 g/mol
x/160 = 2/250
250x = 2 ×160
x= 2 × 160/250
x= 1.28 g
Read the following graduated cylinder.
How many ML?
Answer:
12.8 mL
Explanation:
the bolded bar indicates a count of 5. counting from there would add up to 8/10ths of a mL.
A neutron collides with a nitrogen atom, resulting in a transmutation. Balance the equation.
on + '
NX+1H
Identify the unknown product by identifying the unknown letters.
Ais
Z is
X is
Answer:
The answer is ¹³₆C
Explanation:
searched it up
If 0.654 g of oxygen dissolves in 1.5 L of water at 1.65 atm, at what pressure (in atm) would you be able to dissolve 1.35 g in the same amount of water?
Explanation:
dylalove464
06/11/2020
Hello,
In this case, we first compute the moles of oxygen in 0.654 g and 1.35 g by using its molar mass (32 g/mol):
Then, by using the ideal gas equation at the both states, given the same both temperature and volume:
We compute the volume at the second moles:
Best regards.
Answer:
3.41
Explanation:
:)
Suppose I have enough ingredients to make 25 cookies, but when I go to bake them, I only get 5. What percent yield did I obtain?
Answer:
Explanation:
What is the "theoretical yield" of cookies from each of the "reactants?"
Theor. yield from eggs
=
12
eggs
×
24 cookies
1
egg
=
288 cookies
Theor. yield from vanilla
=
24
tsp vanilla
×
24 cookies
1
tsp vanilla
=
576 cookies
Theor. yield from salt
=
82
tsp salt
×
24 cookies
0.5
tsp salt
=
3936 cookies
Theor. yield from baking soda
=
84
tsp baking soda
×
24 cookies
0.5
tsp baking soda
=
4032 cookies
Theor. yield from chocolate chips
=
3
cups chocolate chips
×
24 cookies
1.333
cups chocolate chips
=
54 cookies
Theor. yield from sugar
=
11
cups sugar
×
24 cookies
0.5
cup sugar
=
528 cookies
Theor. yield from brown sugar
=
4
cups brown sugar
×
24 cookies
0.5
cup brown sugar
=
192 cookies
Finally, "we leave it as an exercise for the student" to calculate that
Theor. yield from margarine = 72 cookies
b. Identify the limiting reactant
The limiting reactant is the amount of chocolate chips because they can produce the smallest amount of cookies.
c. Determine the theoretical yield
The theoretical yield is 54 cookies, because that is all you can get from the chocolate chips provided.
The percent yield obtained on baking the cookies is 20 % and the theoretical yield is 25 cookies.
What is percent yield?Percent yield is defined as the ratio of actual yield to the theoretical yield multiplied by 100. If the actual and theoretical yield are same then the percent yield is 100%.If actual yield is less than the theoretical yield then the percent yield is less than 100%.Reason of this condition arising is the incompletion of reaction or loss of sample during recovery process.
In cases where percent yield is over 100% it indicates that more sample is recovered than the predicted amount.This condition arises when there are other simultaneous reactions taking place leading to the formation of product. It can also arise if there is incomplete removal of impurities from the sample .
As cookies obtained is 5 it is observed yield while 25 is theoretical yield so the percent yield, 5/25×100=20%.
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Explain why rubbing an alkali like bicarbonate of soda onto an acidic bee sting can ease the pain ?
Which atom attracts electrons most strongly? br F Rb
Fluorine has the highest electronegativity in comparison to other elements therefore, the F atom attracts electrons most strongly.
What is electronegativity?The electronegativity of an atom measures the tendency of an element to attract the bonded electrons pairs towards itself. The electronegativity of an atom is determined with respect to another bonded atom.
Electronegativity can be described as a chemical property of an atom or a functional group to attract electrons toward itself. The electronegativity of an atom depends on the atomic number and the distance of valence electrons from the charged nuclei.
When two different atoms are bonded through a bond. More electronegative will attract the electron density of the bond towards itself.
As we know, the electronegativity decreases as we move down the group in the periodic table. Fluorine is the most electronegative element in the periodic table therefore, Fluorine (F) will attract the electrons toward it most strongly.
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Which has more molecules in it 10g H, 0 or 10g NaCl*
A)010g of H0
B)10g of NaCl
C)They have the same number of molecules
D)Cannot be determined
Answer:
10 grams of hydrogen
Explanation:
lime water turns milky when carbon dioxide gas passed through it and on further exposure to carbon dioxide the milkiness disappear, why
Resultant carbon dioxide passed through limewater in the right tube, producing a milky solution due to precipitation of the insoluble suspension of calcium carbonate: ... The milkiness disappears since calcium bicarbonate is water-soluble.
Witch part of an atom is mostly empty space?
when potassium chloride is dissolved in water *
a)heat is given off
b)heat is taken in
c)temperature stays same
Answer:
Option B . heat is taken in
Answer:
B
Explanation:
we need to eat,drink,and sleep to be healthy
The photograph below shows the East African Rift Valley in Africa. Which tectonic movement
of Earth’s crust is most likely responsible for this feature?
Answer:
divergence of continental crust
Explanation:
If the half life of iridium-182 is 15 years, how much of a 3 gram sample is left after 2 half-lives?
A) .57 grams
B) .70 grams
C) 2.25 grams
D) .75 grams
Answer:
D. 0.75 grams
Explanation:
The data given on the iridium 182 are;
The half life of the iridium 182, [tex]t_{(1/2)}[/tex] = 15 years
The mass of the sample of iridium, N₀ = 3 grams
The amount left, N(t) after two half lives is given as follows;
[tex]N(t) = N_0 \left (\dfrac{1}{2} \right )^{\dfrac{t}{t_{1/2}} }[/tex]
For two half lives, t = 2 × [tex]t_{(1/2)}[/tex]
∴ t = 2 × 15 = 30
[tex]\dfrac{t}{t_{(1/2)}} = \dfrac{30}{15} = 2[/tex]
[tex]\therefore N(t) = 3 \times\left (\dfrac{1}{2} \right )^2 = 0.75[/tex]
∴ The amount left, N(t) = 0.75 grams
Additional Activities
Direction: Sharpen your understanding in projectile motion. Calculate the maximum height reached and the horizontal range of the given launched angles and initial velocity of a projectile. You may opt to use the Projectile Motion Simulation with Air Friction by AERDEMIR which can be downloaded via Play Store for free.
1. To use the simulator, set the given values as shown in the left.
Start Angle = Launched Angle = refer to the table Start Velocity = Initial Velocity = 20 m/s
Change the gravitational acceleration to 9.8 only Delete the values in Air Density and Drag Coefficient
2. Deactivate the friction force by tapping the icon indicated in the above image.
The maximum height of an object, given the initial launch angle and initial velocity is found with:
h = v2 is in2θi 2g
h = v i 2 sin 2 θ i 2 g.
2. Which element below would be the best choice when creating a covalent molecule with an
Oxygen atom?
A. Na
B. Mg
C. Ne
D. O
