Chemistry Basics

What is a chemical reaction?

• A chemical reaction is a biological process.

• A chemical reaction is a mathematical equation.

• A chemical reaction is a physical change in matter.

• A chemical reaction is a process that leads to the transformation of one set of chemical substances to another.

How many elements are there in the periodic table?

• 92

• 118

• 64

• 150

What is the smallest unit of an element?

• molecule

• cell

• atom

• compound

What holds atoms together in a chemical bond?

• Sharing or transfer of electrons

• Repulsion of neutrons

• Attraction of protons

• Absorption of photons

What are the three common states of matter?

• plasma

• solidus

• vapor

• solid, liquid, gas

What happens to atoms in a chemical reaction?

• Atoms are rearranged to form new substances.

• Atoms are destroyed completely.

• Atoms are converted into energy.

• Atoms remain unchanged.

Which group of elements are known as the noble gases?

• Fluorine, Chlorine, Bromine, Iodine, Astatine, Tennessine

• Helium, Neon, Argon, Krypton, Xenon, and Radon

• Lithium, Sodium, Potassium, Rubidium, Cesium, Francium

• Hydrogen, Oxygen, Nitrogen, Carbon, Sulfur, Phosphorus

What is the charge of a proton?

• Zero

• Negative

• Positive

• Neutral

What is the atomic number of carbon?

• 7

• 8

• 5

• 6

In which state of matter do particles have the most energy?

• Plasma

• Solid

• Gas

• Liquid