was an ancient Greek philosopher known for his influence on modern science, believed that atoms were indivisible and indestructible
Mendeleev
Dalton
Democritus
Rutherford
unreactive in chemical reactions due to their full valence
halogens
alkali metals
noble gases
solids
the weighted average of the mass of the atoms in a naturally occurring sample of the element
atomic number
atomic mass
atomic size
electronegativity
the number of protons in the nucleus of an atom of that element
mass number
a chemist who used the noble gases to explain why atoms form certain kinds of ions and molecules
Gilbert Lewis
17. groups 1A, 2A, and 3A--metals
Lose electrons
grow electrons
make electrons
gain electrons
groups 5A, 6A, and 7A--nonmetals
tiny central core of an atom composed of protons and neutrons
nucleus
neutron
orbitals
energy level
subatomic particles with no charge
protons
neutrons
electrons
subatomic particles with positive charge
subatomic particles with negative charge
The mass in an atom comes from both the ❌ and the ❌. Each particle is the equivalent of ❌ a.m.u. The electrons have almost ❌ mass.
If you have the mass number and the atomic number, you need to subtract the ❌, which represents the number of ❌, from the mass number to get the correct number of ❌.
If you have the mass number and the number of neutrons, you need to subtract the number of ❌ from the ❌ to get the correct number of ❌.
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
❌ are atoms that have an unequal number of protons and ❌. If they are atoms that have lost electrons they are ❌ and are called ❌s. If they are atoms that have gained electrons, they are ❌ and are called ❌.
