Chapter 2: Atoms

Question 1

Nucleus contains:

Answer 1

Protons and neutrons
(Which determines the atomic weight — electrons in electron cloud are negligible)

Atomic Mass (protons + neutrons combined) - protons (from atomic number) = # of neutrons

Question 2

Atomic Number is equal to the amount of…?

Answer 2

Protons and Electrons (charges cancel —> atom carries neutral charge)

Question 3

I , Mo, Ag, Au, Hg, Pb, Xe, W, Pt, Sn

Answer 3

Iodine, Molybdenum, Silver, Gold, Mercury, Lead, Xenon, Tungsten, Platinum, Tin

Question 4

^A_Z X

What is A, Z, and X?

Answer 4

A: Mass Number
Z: Atomic Number
X: Atomic symbol

Question 5

_______ is defined as the average mass of naturally (stable) occurring isotopes calculated using natural abundance as a weighting factor.

Answer 5

Atomic mass

If no stable isotopes are found in nature — the atomic mass is the based on the longest lived isotope.

Question 6

Name of Group 1A:

Li, Na, K, Rb, Cs, Fr

Answer 6

Alkali metals

Question 7

Name of Group 2A:

Be, Mg, Ca, Sr, Ba, Ra

Answer 7

Alkaline Earth Metals

Question 8

Name of 5A Group:

N, P, As, Sb, Bi, Mac

Answer 8

Pnictogen

Question 9

Name of 6A Group:

O, S, Se, Te, Po

Answer 9

Chalcogen

Question 10

Name of 7A Group:

F, Cl, Br, I, At

Answer 10

Halogen

Question 11

Name of Group 8A:

He, Ne, Ar, Kr, Xe, Rn

Answer 11

Noble Gases

Question 12

Period Table Trends:

Answer 12

Less metallic / decreased atom size going towards the right

Atom size increases / Atoms become more metallic going down

Metals (LEFT) | Nonmetals (RIGHT)

Question 13

Maximum Number of electrons in n-th shell formula:

Answer 13

2 * n²

(For the first 4th shells)

Question 14

[CAS] Group Number = ?

Answer 14

Number of Valence Electrons

Question 15

Period Number = ?

Answer 15

The shell holding the valence electrons