|
|
|
2
|
something we use to study things that are too large or too small to be seen properly
|
|
6
|
electrons are grouped into __ levels
|
|
7
|
tiny particles that make up matter
|
|
9
|
atomic number tells us how many __ are in an atom
|
|
10
|
negatively charged atomic particle
|
|
11
|
this is equal to the number of protons and neutrons in an atom
|
|
12
|
in a neutral atom the number of protons equals the number of __
|
|
14
|
substances that are made of only one type of atom
|
|
16
|
the greek philosopher who was the first to come up with a model for the atom
|
|
19
|
positively charged atomic particle
|
|
20
|
there are over __ types of atoms
|
|
|
