bio lecture 2

Question 1

matter

Answer 1

anything that takes up space and has mass

Question 2

element

Answer 2

a substance that cannot be broken down to other substances by chemical reactions

Question 3

compound

Answer 3

a substance consisting of two or more elements in a fixed ratio

Question 4

Neutrons

Answer 4

no electrical charge

Question 5

atom

Answer 5

is the smallest unit of matter that still retains the properties of an element

Question 6

Protons

Answer 6

positive charge

Question 7

Electrons

Answer 7

negative charge: form a ”cloud” around the nucleus

Question 8

atomic number

Answer 8

is the number of protons in its nucleus

Question 9

mass number

Answer 9

protons + neutrons in the nucleus

Question 10

Atomic mass

Answer 10

the total mass of an atom, which is made up of protons, neutrons, and electrons

Question 11

Isotopes

Answer 11

atoms of the same element that contain an identical number of protons, but a different number of neutrons

Question 12

Radioactive isotopes

Answer 12

atoms that contain an unstable combination of neutrons and protons, or excess energy in their nucleus.

Question 13

potential energy

Answer 13

the energy that an object stores due to its position or internal structure, and has the ability to do work

Question 13

Energy

Answer 13

the capacity to cause change

Answer 14

a group of electrons in an atom that are grouped around the nucleus according to their energy

Question 15

Valence electrons

Answer 15

are those that occupy the valence shell (FIX LATER)

Question 16

single bond

Answer 16

one pair of electrons shared, indicated by a single line between the atoms: H—H

Question 17

Double bond

Answer 17

2 pairs of electrons shared, indicated by a double line between atoms
0==0

Question 18

Covalent bond

Answer 18

atom shares electron with each other

Question 19

Electronegativity

Answer 19

is an atom’s attraction for the electrons of a covalent bond

Question 20

nonpolar covalent bond

Answer 20

atoms share the electrons equally

Question 21

polar covalent bond

Answer 21

one atom is more electronegative; atoms do not share the electron equally. causes a partial positive or negative charge for each atom or molecule

Question 22

ionic bond

Answer 22

attractions between positive charge ion and a negative charge ion.

Question 23

cation

Answer 23

a positively charged ion

Question 24

anion

Answer 24

a negatively charged ion

Question 25

Hydrogen Bonds

Answer 25

forms when the hydrogen plus charge atom is attracted to a negative charge atom such as oxygen or nitrogen atom

Question 26

van der Waals interactions

Answer 26

occur only when atoms and molecules are very close together

Question 27

Chemical reactions

Answer 27

the making and breaking of chemical bonds

Question 28

reactants

Answer 28

the starting molecules of a chemical reaction

Question 29

products

Answer 29

The final molecules of a chemical reaction

Question 30

polar molecules

Answer 30

a molecule in which one end of the molecule is slightly positive, while the other end is slightly negative.

Question 31

cohesion

Answer 31

attraction of molecules to the same kind

Question 32

surface tension

Answer 32

how hard it is to break the surface of a liquid

Question 33

adhesion

Answer 33

the attraction between 2 different substances

Question 34

Kinetic energy

Answer 34

the energy of motion

Question 35

Thermal energy

Answer 35

a measure of the total amount of kinetic energy due to molecular motion

Question 36

Temperature

Answer 36

represents the average kinetic energy of molecules

Question 37

Specific heat

Answer 37

amount of heat must be absorbed/lost for 1 g of substance to change its temp by 1C

Question 38

Heat of vaporization

Answer 38

is the heat a liquid must absorb for 1 g to be converted to gas

Question 39

solution

Answer 39

a homogeneous mixture of one or more solutes dissolved in a solvent.

Question 40

solvent

Answer 40

is the dissolving agent of a solution

Question 41

solute

Answer 41

the substance that is dissolved

Question 42

aqueous solution

Answer 42

one in which water is the solvent

Question 43

hydrophilic

Answer 43

ones agility to interact with water. ex: mix or dissolve

Question 44

hydrophobic

Answer 44

can't interact with water tending to repel water