Answers AA-F26 Physical ScienceCumulative Exam

Cumulative Exam — Cumulative exam Answers

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Carlos is making phosphorus trichloride using the equation below. 2P +3Cl2 _PCl3What coefficient of PCl3 would show that the law of the conservation of mass is represented in the chemical equation?

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Hsaio manages the finances for her company and has a particularly large amount of money budgeted for the purchase of calcium chloride, or CaCl2. Which type of company does Hsaio most likely own?

a snow-plowing service

a cosmetics factory

a pottery art studio

a catering business

How long will a radioactive isotope decay?

until it reaches its half-life

until there is no more material

until it becomes a different, stable element

until the neutrons are returned to the base element level

A substance is on its fifth half-life. Which approximates the percentages of radioactive and stable isotopes, respectively?

96.9%; 3.1%

3.1%; 96.9%

12.5%; 87.5%

87.5%; 12.5%

A cylinder at left with balls evenly spaced throughout the cylinder has an arrow leading to a cylinder at right cylinder with balls in a layer at its bottom.

condensation

boiling

sublimation

freezing

How does Bohr’s model of the atom compare with Thomson’s model?

They both describe atoms as small, indivisible spheres.

They both describe electrons as moving around the nucleus.

They both describe electrons as being surrounded by the positive matter.

They both describe atoms as being made up of positive and negative matter.

What is a main difference between a mixture and a pure substance?

A mixture is only a liquid, but a pure substance can be in any state.

A mixture looks the same throughout, but a pure substance does not.

A mixture can vary in composition, but a pure substance has a set composition.

A mixture can be made up of a single compound, but a pure substance cannot.

This chart lists four elements from the periodic table.Atoms from which two elements would form ionic bonds?

calcium and gold

gold and argon

argon and iodine

iodine and calcium

Which coefficient is needed in front of NaNO3 to balance the equation Na2S + Zn(NO3)2 → ZnS + _NaNO3?

A sample of a solid nonmetal is compared to a sample of a solid metal. Both samples have the same volume. What is the most likely difference between the two samples?

The nonmetal has more mass.

The nonmetal takes up more space.

The metal has more mass.

The metal takes up more space.

The volume of a gas decreases from 15.7 m3 to 11.2 m3 while the pressure changes from 1.12 atm to 1.67 atm. If the initial temperature is 245 K, what is the final temperature of the gas?

117 K

230 K

261 K

512 K

Which ingredient would a company that makes super-sour candy most likely use in large quantities?

nitric acid

zinc hydroxide

citric acid

calcium hydroxide

A researcher is using a particle accelerator in an experiment studying isotopes. How can the researcher change one isotope into a different isotope of the same element?

by removing valence electrons

by adding valence electrons

by adding or removing protons

by adding or removing neutrons

An atom of carbon (C) forms covalent bonds with two atoms of oxygen (O) to form carbon dioxide. How are the valence electrons of these atoms rearranged to form the bonds?

Electrons are transferred from the carbon atom to the oxygen atoms.

Electrons are transferred from the oxygen atoms to the carbon atoms.

Many valence electrons are shared between the atoms.

A few valence electrons are shared between the atoms.

Kenneth ran a marathon (26.2 miles) in 5.5 hours. What was Kenneth’s average speed? (Round your answer to the nearest tenth.)

0.2 mph

4.8 mph

5.5 mph

144.1 mph

Which properties do metalloids share with metals?

Both are shiny and are brittle.

Both are very conductive and are dull.

Both are brittle and are gases at room temperature.

Both are shiny and are solid at room temperature.

What is the chemical formula for sulfur trioxide?

SO3

SfO3

SfO

Sonya reads the element riddle below.I am shiny. I form +1 ions. There’s more!I am the most reactive metal in Period 4. Who am I?Which element is the answer to the riddle?

krypton

potassium

sodium

bromine

The diagram shows a toy car on a number line.