9

18

19

10

5

10

15

20

7

7.01

14.01

21.01

number of neutrons

number of protons

number of isotopes

atomic mass

Li, Be, B, C, N, O, F, and Ne

He, Ne, Ar, Kr, Xe, and Rn

B, Si, As, Te, and At

Sc, Ti, V, Cr, Mn, Fe, Co, Cu, Ni, and Zd

Chemical Symbol

Period

Family

Metals

Nonmetals

Metalloids

Poor conductor of heat

Brittle and dull

Good conductor of electricity

Does not react with acids

Periods

Metals

Groups

Nonmetals

Metal

Nonmetal

Metalloid

Iodine

Seaborgium

Neon

Gold

Aluminum

Neon

Nickel

Hydrogen

The quantum mechanical model considers electrons as having both particle-like and wave-like properties, represented by probability distributions called orbitals, allowing for more accurate predictions compared to Bohr's model.

The quantum mechanical model only considers electrons as particles, ignoring their wave-like properties.

The quantum mechanical model uses circular orbits for electrons, similar to Bohr's model.

The quantum mechanical model predicts electron positions with absolute certainty, unlike the probabilistic nature of Bohr's model.