Biology 1 Chapter 2

Question 1

Matter

Answer 1

Refers to anything that takes up space and has mass

Question 2

Atom

Answer 2

An atom is the smallest part of an element that displays the properties of the element

Question 3

Subatomic particles

Answer 3

Protons. Neutrons. Electrons.
Protons and neutrons are located within the nucleus of an atom and electrons move about the nucleus

Question 4

Atomic number

Answer 4

Number of protons housed in the nucleus

Question 5

Mass number

Answer 5

The sum of the protons and neutrons within the nucleus

Question 6

Isotopes

Answer 6

Atoms of the same element that differ in the number of neutrons

Question 7

Valence shell

Answer 7

Regardless of how many electron shells and atom has the outermost shell is called the valence shell

Question 8

octet Rule

Answer 8

In Adams with more than 1 shell the valance shell is most stable when it has 8 electrons

Question 9

Molecule

Answer 9

Exists when 2 or more of the same type of atoms bond together , It is the smallest part of a compound that retains its chemical properties

Question 10

Compound

Answer 10

Molecule containing atoms of at least 2 different elements

Question 11

Ion

Answer 11

Charged particles are called ions

Question 12

Ionic bond

Answer 12

Ionic compounds are held together by an attraction between negatively and positively charged ions

Question 13

Covalent bond

Answer 13

Results when 2 atoms share electrons in such a way that each atom has an octet of electrons in the outer shell

Question 14

Non-polar covalent bond

Answer 14

When the sharing of electrons between 2 atoms is equal

Question 15

Electronegativity

Answer 15

The atom that has a greater attraction for a shared pair of electrons has a greater electronegativity

Question 16

Polar covalent bond

Answer 16

When electrons are not shared equally

Question 17

Hydrogen bond

Answer 17

Caused by the attraction of a slightly positive hydrogen to a slightly negative atom in the vicinity…
Carbon dioxide for example
DNA is held together by hydrogen bonds. To unzip DNA You have to break the hydrogen bonds.

Question 18

Properties of water

Answer 18

Water has a high heat capacity
Water has a high heat of evaporation
Water is a solvent
Water molecules are cohesive and adhesive
Frozen water Is less dense than liquid water

Question 19

Solution

Answer 19

Contains dissolved substances Which are then called solids

Question 20

Cohesion

Answer 20

Refers to the ability of water molecules to cling to each other due to hydrogen bonding

Question 21

Adhesion

Answer 21

Refers to the ability of water molecules to cling to other polar surfaces

Question 22

Surface tension

Answer 22

Because water molecules are attracted to each other they cling together where the liquid surface is exposed to air. The stronger the force between molecules in a liquid the greater the surface tension. Water’s high surface tension makes it possible for humans to skip rocks on water

Question 23

Acid

Answer 23

Substances that dissociate in water Releasing hydrogen ions

Question 24

Bases

Answer 24

Substances that either take up hydrogen ions or release hydroxide ions

Question 25

Buffer

Answer 25

Chemical or combination of chemicals that keeps PH within normal limits