Chemistry review

Question 1

What is an element

Answer 1

A pure substance that cannot be broken down into simple substances. Consists of one type of atom.

Question 2

What is an atom?

Answer 2

Smallest component of an element and retains the properties of that element.

Question 3

3 subatomic particle

Answer 3

Protons (positive charge)
Electrons (Negative Charge)
Neutrons (Neutral Charge)

Question 4

Atomic Number

Answer 4

Determined by number of protons which equals to the number of electrons

Question 5

Mass number

Answer 5

Number of protons+neutrons

Question 6

Neutrons

Answer 6

Mass Number - Atomic Number

Question 7

Isotopes

Answer 7

Atoms of the same element that have a different mass number hence different number of neutrons.

Question 8

Radioisotopes

Answer 8

Isotopes that break down and decay to emit radiation

Question 9

Half life

Answer 9

Radioisotopes have half life which mean that the amount of time it takes for half of the atoms in a sample to decay

Question 10

Columns of a periodic table

Answer 10

groups/ families

Question 11

Rows of periodic table

Answer 11

periods

Question 12

alkali metals

Answer 12

highly reactive and with one electron

Question 13

noble gases

Answer 13

full valence shell and are inert.

Question 14

Molecule

Answer 14

made of 2 or more atoms of the same or different element. Smallest unit of the substance.

Question 15

Organic molecules

Answer 15

Carbon based. Bonded to each other and to hydrogen. Can include other atoms of nitrogen, oxygen, phosphorus, and sulfur.

Question 16

Biochemistry

Answer 16

Study of the activity and properties of biologically important molecules in order to understand their functions in the cell and in living systems.

Question 17

Valence electrons

Answer 17

electrons of the outermost shell of an atom. Determine reactivity of the atom.

Question 18

Why do atoms bond

Answer 18

To fill the outermost valence shell(octet rule). Once that is done the atom is stable.

Question 19

Intramolecular forces

Answer 19

force that holds atoms together within a molecule. 2 types: covalent and ionic bonds.

Question 20

Ionic Bonds

Answer 20

attractions between ions formed when metals lose electrons to non-metals

Question 21

cations

Answer 21

an atom LOSES electrons, it acquires a positive charge

Question 22

anion

Answer 22

an atom gains electrons, it acquires a negative charge

Question 23

covalent bonds

Answer 23

non-metallic atoms share electrons. 2 types: non polar and polar. determined by electronegativity which is the different ability for atoms to attract electrons.

Question 24

non polar

Answer 24

If identical atoms bond, neither atom is more electronegative, therefore they share electrons example O2, Br2. Molecule is referred to as non polar molecule and the bond is non polar covalent bond.

Question 25

Polar

Answer 25

two non-identical non-metals share electrons, one atom is more electronegative, therefore they don’t share electrons equally. Gives more electronegative atoms a partial negative charge and less electronegative atoms a partial positive charge.

Question 26

Electronegativity difference

Answer 26

If the electronegativity difference is great enough, more than 1.7, then the electrons actually transfer and ions are formed!

Question 27

Intermolecular atoms

Answer 27

forces BETWEEN molecules
weaker
two types: hydrogen bonding and hydrophobic interactions.

Question 28

Hydrogen bonding

Answer 28

weak association between an atoms with a. partial negative charge and a hydrogen with a partial positive charge. Weaker than ionic and covalent bond

Question 29

Hydrophobic Interaction

Answer 29

-Hydrophobic is when non polar molecules do not have attractive interactions with water molecules.
-The effect is that there is a natural clumping of non polar molecules in water.

Question 30

Hydrophilic

Answer 30

• when polar molecules have attractive interactions with water molecules.
• Like dissolves like