Chemistry

The __ tells how many energy levels on any atom.

period

Center of atom containing protons (positive necleons) and and neutrons (neutral nucleons)

atomic nucleus

Number of protons in an atom.

atomic number

Number of protons and neutrons in the nucleus of an atom.

Mass number

Atoms of a particular element may have different numbers of neutrons and, therefore, different __ __.

mass numbers

What do you not get mass numbers from? How do you get it instead?

periodic table. add protons and neutrons

Atoms which have the same number of protons but different numbers of neutrons.

isotopes

Almost all elements have two or more naturally occuring __.

isotopes

The elements that have two or more naturally occurring isotopes, one or more of these isotopes may be __.

radioactive

Symbol for an element which also includes the mass number and atomic number.

complete symbol

Where does the mass number and the atomic number appear in a complete symbol?

mass number: top left
atomic number: bottom left

Are number of protons and number of electrons for atoms, which are neutral, equal to each other?

yes

_ _ are included with the element symbol on the Periodic Table.

Atomic numbers

_ _ are NOT included on the Periodic Table.

Mass numbers

What is the outer most shell called on an atom?

valence shell

How do you get the number of neutrons?

mass number - atomic number or number of protons

Cations (+) _ electrons
Anions (-) _ electrons

lose
gain

What are ions? And do protons and electrons equal each other?

charges. no

Atoms are what? Do protons and electrons equal each other?

neutral. yes