Chapter 2: Atoms and Periodic Table

Question 1

Element

Answer 1

pure substance that cant be broken down any further by chemical means

Question 2

Compound

Answer 2

pure substance formed chemically by two or more elements

Question 3

Atoms

Answer 3

All matter is composed of same building blocks called matter
composed of 3 subatomic particles
neutron +0 ( mass number - protons)
electron -1 (valence electron; same number as proton if neutral)
proton +1 (number of element)

Question 4

Atomic weight vs atomic mass vs atomic number

Answer 4

atomic weight: amu on periodic table
Atomic mass: protons plus neutrons
atomic number: number of protons

Question 5

mass (amu)

Answer 5

proton and neutron: 1 amu
electron: negligible

Question 6

Isotopes

Answer 6

atoms of the same element but different number of neutrons

Question 7

row

Answer 7

Periods

Question 8

columns

Answer 8

group

Question 9

Main Group elements

Answer 9

1a-2a and 3a-8a

Question 10

Transition metal elements

Answer 10

3-12 (in middle)

Question 11

Inner transition elements

Answer 11

outside the main

Question 12

Valence Electrons

Answer 12

chemical properties of an element depend on the most loosely held electrons in the outer most shell (valence shell) highest value of n and these electrons in valence shell is called valence electrons

Question 13

How to determine valence electrons

Answer 13

group number 1A-8A equals number of valence electrons; the chemical properties of the group are similar because they have same number of electron configuration of valence electrons

*He is exception only 2 valence electrons

Question 14

Ionic Bond

Answer 14

transfer of electrons
metal + nonmetal

Question 15

Covalent bonds

Answer 15

sharing of electrons
nonmetal+ nonmetal or metalloid + nonmetal

Molecule: discrete group of atoms that share electrons

Question 16

Ions

Answer 16

Ions are charged species that have an uneven amount of protons and electrons

Question 17

Ionic Compounds

Answer 17

consists of oppositely charged ions that have a strong electrostatic attraction

1) Cations +
2) Anions -

the sum of charges in ionic compound MUST BE ZERO

Question 18

Cations

Answer 18

positively charged ions; metals form cations; more protons than electrons

Question 19

Anions

Answer 19

negatively charged ions; nonmetals form anions; more electrons than protons

Question 20

The octet rule

Answer 20

a main group element becomes stable when it possess a octet of e in outer shell

wants to be like noble gases

Question 21

Aluminum

Answer 21

3+ action

Question 22

Naming Ionic compounds

Answer 22

name the cation by its element name

add “ide” to anion name

Question 23

Naming ionic compounds with compounds of metals with variable charge

Answer 23

name cation by element name, in parenthesis add charge in roman numbers

add “ide” to anion