Physics and Chemistry: Units, Atomic Structure, and Bonding Concepts

kilo

(k)=10³

milli

(m)=10⁻³

1 lb

453.59 g

1 in

2.54 cm

1 mile

1.6093 km

1 kg

2.2046 lb

1 m

1.0936 yd

1 yd

3 ft

12 in

1 ft

1 gal

3.7854 L

60 s

1 min

60 min

1 hr

K

°C+ 273.15

Density

mass/volume

Proton

+1, ~1 u, nucleus

Neutron

0, ~1 u, nucleus

Electron

-1, ~0, outside nucleus

Atomic Number

number of protons

mass number

protons + neutrons

neutral atom

number of protons = number of electrons

First Shell

2 electrons

Second Shell

8 electrons

Trends

Radius ↓ across a period, ↑ down a group

Ionic

metal + nonmetal (transfer)

Covalent

nonmetal + nonmetal (sharing)

Group 1A (alkali metals)

1

Group 2A (alkaline earth metals)

2

Group 6A (chalcogens)

-2

Group 7A (halogens)

-1

Nitrate

Sulfate

Carbonate

Ammonium

Greek Prefixes

1-mono

2-di

3-tri

4-tetra

5-penta

6-hexa

7-hepta

8-octa

9-nona

10-deca

water

ammonia

methane

nonpolar covalent

electrons shared equally, Electronegativity Differences < 0.5

polar covalent

unequal sharing of electrons, Electronegativity Differences 0.5-1.9

ionic bond

the attraction between oppositely charged ions, Electronegativity Differences ≥ 2.0

Linear

180° (2 e- groups)

Trigonal planar

120° 3 bonds, 0 lone pairs

Tetrahedral

109.5° 4 bonds, 0 lone pairs

Pyramidal

107° (3 + lone pair)

Bent

104.5° (2 + 2 lone pairs)

Giga (G)

10⁹ (1,000,000,000)

Mega (M)

10⁶ (1,000,000)

hecto (h)

10² (100)

deka (da)

10¹ (10)

base unit

10⁰

Deci (d)

10⁻¹ one tenth

Centi (c)

10⁻² one hundredth

micro (μ)

10⁻⁶ one millionth

Nano (n)

10⁻⁹ one billionth

pico (p)

10⁻¹² one trillionth

femto (f)

10⁻¹⁵ one quadrillionth

Atto (a)

10⁻¹⁸one quintillionth