Unit Test — Unit test Answers

Which argument best explains the charge of an atomic nucleus?

Rahul sees a flock of birds. He watches as the flying birds land in neat little rows on several power lines. Which change of state does the motion of the birds most closely model?

What are the two parts of an atom?

The density of solid aluminum is 2.70 g/cm3. If a 1g piece of aluminum is dropped in a cup of water, what will happen to the aluminum? (The density of water is 1.00 g/cm3.)

Tijuan mixed a solid and a liquid together in a beaker. He determined that a chemical change occurred.

The descriptions below explain two ways that water is used by plants on a sunny day.I. In a process called transpiration, some liquid water in leaves changes to water vapor. The water vapor is released into the air through tiny pores in the leaves. This allows more liquid water from the soil to be pulled up the roots and stem to replace water lost from the leaves.II. Plants use some of this water in leaves in a process called photosynthesis. During photosynthesis, water and carbon dioxide break apart and recombine to form two new substances, oxygen and glucose.

Which would show an example of how physical changes are reversible?

The diagram shows changes of state between solid, liquid, and gas. The atoms of a substance gain energy during a change of state. Before the change, the atoms are close together and cannot slide past one another. After the change, the substance can fill its container.

Who described atoms as small spheres that could not be divided into anything smaller?

The first model of the atom was developed through

Atom A and Atom B have the same number of protons, but they do not have the same number of neutrons.Which statement describes these atoms?

Venn diagrams are used for comparing and contrasting different topics. The overlapping sections show characteristics that the topics have in common, and the sections that are unique to each topic show the characteristics apply to only that topic.

Scientists in a lab are working with two different samples of the element mercury. They know that the different samples are different isotopes.

Sari is studying four different samples of materials. This table shows the mass and volume of the samples.

The elements in group 17 of the periodic table are all called halogens. All halogens have the same

This is how sodium appears in the periodic table.

Which statement describes a property of a proton?

Who is known as the "father of modern chemistry” because he first organized all known elements into four different groups?

When an atom that has no charge loses two electrons, it becomes a

A substance occupies one half of an open container. The atoms of the substance are closely packed but are still able to slide past each other.What is most likely the phase of the substance?