Chapter 2: Atoms, Molecules, and Ions

Question 1

What are Molecular Compounds

Answer 1

2 or more DIFFERENT (usually non-metal) atoms chemically bound…and also, an entire sample , or a collection/sample of that single molecule (usually non-metal) made of DIFFERENT atoms.

(The atoms in a molecular compound have to be different; they can’t be two of the same atom; Things like H2 and O2 are molecules, but not molecular compounds)

Similar to how ‘compound’ can describe a single H2O compound, or an entire glassful of H2O

structures made of 2 or more atoms (not ions)

Usually non-metals

Question 2

What is a Cathode Ray?

Answer 2

What we called the charged particles/radiation that traveled across a cathode ray tube when a voltage was applied;

These ‘rays’ were later determined to be electrons

Question 3

What is the Charge of an electron in Coulombs?

Answer 3

-1.602E10-19 coulombs

for convenience, this is represented by -1 charge
double this to get a +2 charge, and so forth

Question 4

What is the ‘Angstrom’ a measure of?

Answer 4

Unit of measure for the diameter of atoms

1 Angstrom is 10E-10 meters
Most atoms are between 1 and 5 Angstroms across

Question 5

What is the Charge of a proton in Coulombs?

Answer 5

+1.602E10-19 coulombs

for convenience, this is represented by +1 charge
double this to get a +2 charge, and so forth

Question 6

What is a Diatomic Molecule?

Answer 6

Elements that are more stable when found in twos:

Question 7

What is an Anion?

Answer 7

What an atom becomes if it GAINS an electron

Question 8

What is an Ionic Compound?

Answer 8

Compound made of ions (cations and anions)

Usually between metals and non-metals

Question 9

What does the ‘Law of Constant Composition/Definite Proportions’ state?

Answer 9

The ratios of the components in a given compound are the same across all instances of that particular compound

All compounds have the same component ratios/proportions

Question 10

What is a Cation?

Answer 10

What an atom becomes if it LOOSES an electron (and subsequently develops a positive charge)

Question 11

What is an Ion?

Answer 11

What an atom becomes if it gains or looses an electron

Less stable and more likely to engage in interactions than atoms

Question 12

What does ‘Radioactivity’ describe?

Answer 12

Emission of high energy radiation (oft in the form of particles: gamma, beta, and alpha particles)

Question 13

What is the mass of an electron?

Answer 13

9.10E-28g

Derived from Milikin’s oil drop experiments (because he figured out electrons’ charges and applied them to the mass:charge ratio found with cathode ray experiments

Question 14

What are Subatomic Particles?

Answer 14

Particles of atoms (nucleons and electrons) whose discover helped prove that atoms were not indivisible

Question 15

What are the 4 postulates of Dalton’s Atomic Theory?

Answer 15

1. Everything is made of atoms
2. All atoms of a given element are identical
3. Atoms of one element cannot be changed into atoms of another
4. All compounds have the same component ratios/proportions

Question 16

What are the 7 diatomic molecules from this class?

Answer 16

H2 N2 F2 O2 I2 Cl2 Br2

Br is Bromine, not Boron

Question 17

Which elements on the periodic table are ‘main group’ elements?

Answer 17

Elements in groups 1-2 and groups 13-18

Elements in the “s” and “p” blocks

Question 18

Which elements on the periodic table are “inner transition” metals?

Answer 18

The ones in that two rows of elements that don’t fit on the actual table in the picture

(Lanthanides and Actinoids)

Question 19

Which elements on the periodic table are ‘transition’ metals?

Answer 19

The elements in groups 3-12, excluding the chunk of elements that are off to the side/bottom of the table

Question 20

What elements is represented by the “Br” in the “Have No Fear Of Ice Cold Beer” mnemonic?

Answer 20

Bromine (Br)