Periodic Table Exam

was an ancient Greek philosopher known for his influence on modern science, believed that atoms were indivisible and indestructible

unreactive in chemical reactions due to their full valence

the weighted average of the mass of the atoms in a naturally occurring sample of the element

the number of protons in the nucleus of an atom of that element

unreactive in chemical reactions due to their full valence

a chemist who used the noble gases to explain why atoms form certain kinds of ions and molecules

17. groups 1A, 2A, and 3A--metals

groups 5A, 6A, and 7A--nonmetals

tiny central core of an atom composed of protons and neutrons

subatomic particles with no charge

subatomic particles with positive charge

subatomic particles with negative charge

The mass in an atom comes from both the [blank_start]protons[blank_end] and the [blank_start]neutrons[blank_end]. Each particle is the equivalent of [blank_start]one[blank_end] a.m.u. The electrons have almost [blank_start]zero[blank_end] mass.

If you have the mass number and the atomic number, you need to subtract the [blank_start]atomic number[blank_end], which represents the number of [blank_start]protons[blank_end], from the mass number to get the correct number of [blank_start]neutrons[blank_end].

If you have the mass number and the number of neutrons, you need to subtract the number of [blank_start]neutrons[blank_end] from the [blank_start]mass number[blank_end] to get the correct number of [blank_start]protons[blank_end].

Valence electrons are the electrons in the highest occupied energy level of an element's atoms, determines the properties of an element

isotopes are positively charged subatomic particles

a cation is an ion with a negative charge

[blank_start]Ions[blank_end] are atoms that have an unequal number of protons and [blank_start]electrons[blank_end]. If they are atoms that have lost electrons they are [blank_start]positive[blank_end] and are called [blank_start]cation[blank_end]s. If they are atoms that have gained electrons, they are [blank_start]negative[blank_end] and are called [blank_start]anions[blank_end].