Chapter 2.4

Question 1

Isotopes

Answer 1

Each of two or more forms of the same element that contain equal numbers of protons but different numbers of neutrons in their nuclei,

Most isotopes are radioactive and not naturally occurring.

Natural abundance: the percentage of naturally occurring isotopes

Question 2

Mass spectrometer

Answer 2

Atoms & molecules can be separated by mass by a mass spectrometer.

x-axis: Mass of particles

y-axis: relative abundance of particles

Question 3

Types of chemical formulas

Answer 3

Molecular Formula: actual number of each type of element in a molecular compound

Structural Formula: gives the connectivity information of the molecule

Ball and Stick model: Convey the 3-dimensional structure of the molecule

Space-filling models: conveys the 3D structure and the relative radii of the atoms.

Perspective Drawings: coney the 3D STRUCTURE BUT W/ pencil and paper (what I did in chem)

Question 4

Diatomic molecules: Memorize

Answer 4

H, N, O, F, Cl, Br, I

Question 5

Network solid elements

Answer 5

Exists as a 3D network of atoms held together by covalent bonds

-All metals

Question 6

Molecular compounds (same as covalent)

Answer 6

Two or more atoms of different elements are held together by a chemical bond in a discreet particle (ex. H2O)

Question 7

Ionic compound

Answer 7

Cations and anions held together by electrostatic forces in a 3D lattice

(NaCl)

Question 8

Network solid compounds

Question 9

Formula Mass and Empirical formulas

Answer 9

Formula mass: the sum of the average atomic masses of each atom in a molecule or formula unit of a compound ( in AMU)

Empirical formula: the smallest whole-number ratio of each type of element in a compound. Sometimes this is used to find atomic weight.

-Is the formula used for ionic & network solid compounds

Question 10

Isomers

Answer 10

Compounds with the same chemical formula but different molecular structures.

-If they have different connectivity, they are structural isomers

-If they have the same connectivity but different 3D structures, they are spatial isomers or stereoisomers

Question 11

Mole

Answer 11

The mole: defined as a number of atoms in exactly 12g of Carbon 12
1 mol is equal to Avogadro’s Number
For the sig figs do 6.022
Mass of one mole is the molar mass