Nucleus= protons and neutrons. Protons=+1 charge Neutrons= Neutral
All the mass of an atom is in the nucleus.
Electrons are negatively charged. Virtually no mass. -1 charge
23 <--- Mass Number. Protons and Neutrons. These two things have mass, think about that to remember.
11<--- Atomic Number (Number of protons/electrons)
Isotopes= Extra Neutrons.
GROUP 0 = NOBLE GASES (Helium)
GROUP 1 = ALKALI METALS (Potassium)
GROUP 7 = HALOGENS (Chlorine
Same group means the same number of outer electrons.
2, 8, 8.
Lose or gain electrons to form charged particles called IONS.
Strongly attracted to each other.
[Na]+ [Cl]-. <------- Ionic bond