Two pieces of clay have been molded into two different shapes. The mass of clay can be measured using a scale, such as those shown here. What do the readings on the digital scales indicate about the two pieces of clay?

Which of the following statements is correct? Choose all that apply.

What is the correct formula used to find the volume of a rectangular prism?

What is the correct formula to find the volume of an irregularly shaped object?

Which of the following relationships are true? Choose all that apply.

In the photo, the juice is shown in its solid state and in its liquid state. What appears to have changed about the juice when it changes state? Choose all that apply.

Which of the following are requirements for something to be a physical property? Choose all that apply.

Which of the following properties are physical properties? Choose all that apply.

Which of the following are chemical properties?

Thermal conductivity is a property that describes how quickly a substance warms or cools. What type of property is thermal conductivity?

The walls of your refrigerator must keep as much heat as possible from getting inside the refrigerator. The refrigerator will use a lot of this material, so the cost must be low. Which material would you use to make the refrigerator's inner walls? Why?

The refrigerator needs a thermometer to respond quickly to temperature changes and keep the food inside cold. The thermometer is small, so it can be made out of pricier materials. Which material would you use to make the thermometer?

Even though an iceberg and the water that surrounds it are made up of the same substance, the iceberg is able to float. Why is this?

A submarine is able to raise and lower itself underwater. A rock sinks when it is dropped in a pool because it is denser than water. A piece of wood floats in the pool because it is less dense than water. What could the submarine change in order to sink or float? Choose all that apply.

A submarine fills a special storage area known as a ballast with water in order to increase its density. This allows it to dive deeper in the ocean. When a submarine needs to rise rapidly, compressed air is used to push the water out of the ballast. What effect does replacing the water in the ballast with air have on the submarine?

Chemists use the periodic table to organize the elements. What are some ways in which this organization is useful? Select all that apply.

A thermoacoustic generator transforms thermal energy into electrical energy. Thermal energy is transferred to a gas by a heat exchanger. The thermal energy causes the gas particles to vibrate rapidly and generate a sound wave. These vibrating gas particles are then used by an alternator to generate electrical energy. The gas used in this kind of generator must be nonreactive to avoid the danger of fire. Using heavier gases increases the amount of electrical energy generated. Which two elements on the table are most likely to be good choices for use as a gas in a thermoacoustic generator?

Early periodic tables organized elements based on their atom masses and their properties. Why might this not be the best way to organize a periodic table? Select all that apply.

Which pair of elements is most likely to have similar properties?

Which properties do atoms of the same element share? Select all that apply.

The three elements in the photos all belong to the same group, or column, of the periodic table. These elements all produce salts when they react with metals. What are some differences between these elements?

Imagine that you have a sample of a substance. You cannot physically separate that substance into components. You also cannot chemically separate that substance into components. Which of the following are true about your sample? Choose all that apply.

What is the atomic number of Carbon?

Chemists use the periodic table to organize the elements. What are some ways in which this organization is useful? Select all that apply.

What is the second lightest element in group 2?

What is the symbol for the element with atomic number 92?

Which element has atomic number 6?

What is the lightest element in group 17?

What property do all the elements in group 18 have in common?

What is the symbol for the element Copper?

What is the name of the element with atomic number 50?

3. What is the atomic weight of argon?

Which of these molecules show atoms that have joined together?

Which molecules are also compounds?

Which statements are true about molecules and compounds? Circle all that apply.

For every molecule of sulfur dioxide, the ratio of sulfur atoms to oxygen atoms is ____. (sulfur=yellow, oxygen=red, nitrogen=orange)

In a molecule of nitrogen dioxide, the ratio of nitrogen atoms to oxygen atoms is ____. (sulfur=yellow, oxygen=red, nitrogen=orange)

For every molecule of nitrous oxide, the ratio of nitrogen atoms to oxygen atoms is ____. (sulfur=yellow, oxygen=red, nitrogen=orange)

In a molecule of sulfur trioxide, the ratio of sulfur atoms to oxygen atoms is _____. (sulfur=yellow, oxygen=red, nitrogen=orange)

1. Water, table salt, and tin metal are all pure substances. Which of these pure substances are compounds?

Molecules are atoms held together by attractive forces. Which could be a way to model a simple molecule of three hydrogen atoms joined to a nitrogen atom?

What might explain the differences in properties of the two pure substances: ice and copper metal? Choose all that apply.

Which statement matches the model below?

Which statement matches the model below?

Which statement matches the model below?

Which of the following might explain differences in properties between oxygen and ozone when both substances are made of the same type of atoms?

Diamond and graphite are both made of carbon atoms. However, they have different properties because their atoms are arranged in different ways. Diamonds are very hard. Cut and polished diamonds bounce light in different directions. Graphite is a dark, dull gray and easily rubs off onto paper. What could explain the differences in diamond and graphite?

What does each green sphere represent?

What does each gray line represent?

Which of the following can be observed from the model of water?

Another way to model water is with letters and lines like this H-O-H. What is one way that these models are different?

Based on the models of these structures, white phosphorous is a ________, red phosphorous is a ________, and both are examples of a(n) _______.

What subatomic particle is specifically responsible for combining the atoms together to form a new substance?

Which are ways to identify if a chemical reactions happened?

Which of the following is NOT true of a chemical change?

Which of the following would not be evidence of a chemical change?

Atomic number is the number of _____ in an atom.

What are the two subatomic particles found inside the nucleus?

Which two subatomic particles have approximately the same mass?

What two subatomic particles are added up to make the atomic mass of an atom?

Which subatomic particle changes the element's identity?

Which subatomic particle has a positive charge?

Which subatomic particle has a negative charge?

Which subatomic particle is neutral, or has no charge?

What does the atomic number represent on the periodic table?

Which number determines how the periodic table is arranged?

All the elements in the same period have the same ____.

All the elements in the same group have the same ______.

Reactivity increases when moving from ________ and _______ on the periodic table.

What are the rows of the periodic table called?

What are the columns of the periodic table called?

_____ is a mixture, _____ is an element, and ______ is a compound.

______ are not chemically combined, whereas ______ are chemically combined.

How many elements have to be present for a compound to form?

How many different elements are in C6H12O6?

Which of the following would not be a compound?

Which is true of pure substances?

In an element, all atoms are made of the same type.

______ can be broken down into simpler substance.

_______ always form in a fixed ratio. An example is water. Another example is salt.