Q: In one of the steps of the carbon cycle, a person exhales a molecule of carbon dioxide (CO2) into the atmosphere. Which of the following is most likely to happen next to the atom of carbon in this molecule? OPTIONS:
- It may be used as part of a sugar in a plant.
- It may become part of a protein in an animal.
- It may be consumed as a fossil fuel is burned.
- It may be decomposed into carbon and oxygen by a bacterium.
A: It may be used as part of a sugar in a plant.

Which scientific model could be used to predict the properties of an element?
OPTIONS:
- closed loop system
- Punnett square
- Periodic Table
- water cycle chart

Periodic Table

Q: Colored alcohol is used in some glass thermometers. When placed in air of different temperatures, the column of alcohol rises or falls in the glass thermometer. Which of the following best explains why the height of the alcohol column changes? ---- OPTIONS:
- The glass contracts when heated.
- The alcohol contracts when heated.
- The glass expands more than the alcohol when heated.
- The alcohol expands more than the glass when heated.

A: The alcohol expands more than the glass when heated.

Use The Periodic Table of the Elements and the information below to answer the question. Magnesium metal (Mg) is grayish-white in color and reacts actively with water. Fluorine (F2) is a greenish-yellow gas at room temperature and is a member of the halogen family. These two elements react to produce magnesium fluoride (MgF2), a chemical commonly used in making windows and lenses. How do the elements magnesium (Mg) and fluorine (F2) produce the compound magnesium fluoride (MgF2)?
===
OPTIONS:
- by nuclear connection
- by physically combining
- by magnetic connection
- by chemically combining

by chemically combining

Question:
In addition to oxygen, which gases make up the largest percentage of Earth's atmosphere?
OPTIONS:
- hydrogen, helium, and water vapor
- hydrogen, methane, and ozone
- carbon dioxide, water vapor, and nitrogen
- carbon dioxide, methane, and helium
Answer:
carbon dioxide, water vapor, and nitrogen

Question:
Sodium chloride, commonly called "table salt," is made up of sodium and chlorine that have been combined chemically. Which term best describes sodium chloride?
OPTIONS:
- Acid
- Atom
- Element
- Compound
Answer:
Compound