Chapter 2

Question 1

matter

Answer 1

occupies space and has mass

Question 2

elements

Answer 2

pure substance; cannot be broken down into anything else

Question 3

compound

Answer 3

substance consisting of two or more elements

Question 4

main four elements in the body

Answer 4

Carbon, Hydrogen, Oxygen, Nitrogen (CHON)

Question 5

emergent properties

Answer 5

characteristics of compounds not usually found in the base elements

Question 6

trace elements

Answer 6

elements needed by the body in small quantities; iron, iodine, fluorine, etc.

Question 7

atom

Answer 7

smallest unit of matter able to retain elemental properties

Question 8

proton

Answer 8

• positive charge
• in nucleus
• has mass

Question 9

electron

Answer 9

• negative charge
• in electron shell
• no mass

Question 10

neutron

Answer 10

• neutral charge
• in nucleus
• has mass

Question 11

nucleus

Answer 11

atoms central core

Question 12

atomic number

Answer 12

number of protons

Question 13

atomic mass

Answer 13

number of protons and neutrons

Question 14

isotopes

Answer 14

same element but with different atomic masses (C12 and C13)

Question 15

radioactive isotope

Answer 15

unstable isotope with decaying nucleus; gives off particles and energy

Question 16

why are radioactive isotopes useful ?

Answer 16

can be used to track and follow certain molecules and show accumulation of certain molecules

Question 17

electron shell

Answer 17

levels of electrons at certain distances from nucleus; determines chemical properties of the atom

Question 18

electron levels 1-4 hold how many electrons each ?

Answer 18

2, 8, 8, 18

Question 19

chemical bonds

Answer 19

attraction between the electrons in two atoms

Question 20

what is the goal of chemical bonds ?

Answer 20

to complete the valence electron shell

Question 21

ionic bond

Answer 21

transferring electrons

Question 22

covalent bond

Answer 22

sharing ≥ 1 electrons

Question 23

how many covalent bonds for Carbon, Hydrogen, Oxygen, Nitrogen

Answer 23

4, 1, 2, 3

Question 24

molecule

Answer 24

≥ 2 atoms covalently bonded

Question 25

electronegativity

Answer 25

attraction of atoms for electrons in covalent bonds

Question 26

nonpolar covalent bond

Answer 26

electrons shared equally between atoms with similar electronegativity

Question 27

polar covalent bond

Answer 27

electrons shared equally between atoms with different electronegativity

Question 28

why are water molecules polar covalent bonds ?

Answer 28

the slightly negative Oxygen and the slightly positive Hydrogen

Question 29

ionic charges in elements are obtained how ?

Answer 29

from the transferring of electrons between one atom to another

Question 30

ion

Answer 30

atom(s) gained / lost an electron; gaining a positive or negative charge

Question 31

what holds together ions in a crystal of table salt

Answer 31

ionic bond (Na+ and Cl-)

Question 32

hydrogen bond

Answer 32

slightly positive Hydrogen atom bonds covalently with another slightly negative atom

Question 33

polar molecule

Answer 33

molecule with polar covalent bond; unequal electron distribution

Question 34

what enables neighboring water molecules to hydrogen bond

Answer 34

the slightly positive Hydrogen atom of one molecule and the slightly negative Oxygen atom in another

Question 35

chemical reactions

Answer 35

make / break / rearrange bonds; leads to a change in composition of matter

Question 36

reactant

Answer 36

starting material in a chemical reaction

Question 37

product

Answer 37

ending material in a chemical reaction

Question 38

why is sold water less dense than liquid water

Answer 38

due to the hydrogen bonds; the bonds freeze spaciously rather then densely

Question 39

how can freezing water crack a boulder ?

Answer 39

the expanding hydrogen bonds will expand in the cracks and then crack the boulder itself

Question 40

solution

Answer 40

homogenous mixture of ≥ 2 substances in a liquid

Question 41

solvent

Answer 41

dissolving agent of a solution

Question 42

universal solvent

Answer 42

water

Question 43

solute

Answer 43

substance being dissolved in a solution

Question 44

aqueous solution

Answer 44

solution using water as solvent

Question 45

why is water the universal solvent ?

Answer 45

(idk) waters polarity; the slightly positive Hydrogen atoms and the slightly negative Oxygen atoms

Question 46

acid

Answer 46

increases Hydrogen (H+) ion concentration by donating H+ ions

Question 47

base

Answer 47

reduces hydrogen (H+) ions by donating hydroxide ions (OH-)

Question 48

pH scale

Answer 48

scale of 0 - 14 (acidic - basic)

Question 49

buffer

Answer 49

substance that’s minimizes changes in pH