Chemistry Vocab

Two nonmetals
One nonmetal + one metal
metal + metal
How do you find the number of neutrons in an isotope?
Subtract the atomic number (or number of protons, respectively) from the mass number given.

How do you determine the number of valence electrons for a neutral atom?

The number of valence electrons is equal to the atom’s main group number.
Chemical Change
Changes the substance by making a new one.

Physical Change

Changes the physical appearance of the substance.
Why don’t noble gases react with other elements?
Their outer shells are full.
Law of Conservation of Mass (real-life scenario)
If you put one L of water in a bottle, it will weigh one kg more.
 a substance made up of two or more elements chemically combined in a fixed proportion by mass.
To find density…
What does the Atomic Number of an element represent?
It is the number of protons the element has.
Which lab tool is used to measure mass?
Triple-beam balance
Conservation of Energy
a principle stating that energy cannot be created or destroyed, but can be altered from one form to another.

What is the best tool to measure liquid volume?


A gradulated cylinder
Mass Number
the total number of protons and neutrons in a neucleus
the total energy of molecular motion in a substance
A measure of the average energy of molecular motion in a substance