Chapter 2

Question 1

Matter

Answer 1

-what organisms are composed of
-anything that takes up space and has mass
-made up of elements

Question 2

Element

Answer 2

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

Question 3

Compound

Answer 3

substance consisting of 2 or more elements in a. fixed ration and have emergent properties
-characteristics are different from its elements
-molecule that contains at least 2 different elements

Question 4

Molecule

Answer 4

formed when 2 or more atoms join together

Question 5

Atom

Answer 5

-what each element consists of
-smallest unit of matter that still retains the properties of an element
-composed of subatomic particles (neutron, proton, electron)

Question 6

Neutron

Answer 6

no electrical charge
-determines isotope

Question 7

Protons

Answer 7

positive charge
-determines element

Question 8

Electrons

Answer 8

negative charge
-determines chemical behavior

Question 9

Dalton

Answer 9

standard unit used for indicating mass on an atomic or molecular scale

Question 10

Atomic number

Answer 10

number of protons

Question 11

Mass number

Answer 11

number of protons+number of neutrons

Question 12

Atoms of same element have

Answer 12

same number of protons but may have different number of neutrons

Question 13

Isotopes

Answer 13

atoms of an element that differ in the number of neutrons

Question 14

Radioactive isotopes

Answer 14

decay spontaneously, giving off particles and energy

Question 15

Energy

Answer 15

capacity to cause change

Question 16

Potential energy

Answer 16

energy that matter has because of its location or structure
-electrons of atom differ in the amount
-electrons state of potential energy=its energy level or electron shell

Question 17

Chemical behavior

Answer 17

determined by distribution of electrons in electron shells

Question 18

Valence electrons

Answer 18

those in outermost shell or valence shell
-determines chemical behavior
-full valence=chemically inert

Question 19

Orbital

Answer 19

3d space where an electron is found 90% of the time

Question 20

Covalent bond

Answer 20

-the sharing of a pair of valence electrons by 2 atoms
-can form between atoms of same or different elements
-the shared e count as part of each atoms valence shell
-single covalent=sharing of 1 pair
-double covalent=sharing of 2 pairs

Question 21

Bonding capacity

Answer 21

called the atoms valence

Question 22

Electronegativity

Answer 22

an atoms attraction for electrons in a covalent bond
-more electronegative=more strongly it pulls e towards itself
-increase to left and up

Question 23

Nonpolar covalent bond

Answer 23

the atoms share the electron equally

Question 24

Polar covalent bond

Answer 24

1 atom is more electronegative so atoms don’t share the electron equally
-unequal sharing causes partial positive or negative charge for each atom or molecule

Question 25

Ionic bond

Answer 25

attraction between an anion and cation -transfer of electrons -complete valence shells but with charges -form ionic compounds and salts

Question 26

Strong vs weak bonds

Answer 26

stronger=covalent weaker=ionic, hydrogen, van der Waals weak-reinforce shapes and adhere molecules to each other, is reversible

Question 27

Ion

Answer 27

charged atom or molecule

Question 28

Hydrogen bond

Answer 28

forms when hydrogen is covalently bonded to one electronegative atom (F, O, N)

Question 29

Van der Waals interactions

Answer 29

attractions between molecules that are close together as a result of electrons distributing asymmetrically and resulting in charges

Question 30

Molecules shape

Answer 30

determined by positions of its atoms valence orbitals -similar shapes can have similar biological effects

Question 31

Chemical reactions

Answer 31

the making and breaking of chemical bonds -reactants=starting molecules -products=final molecules -can be reversible

Question 32

Photosynthesis

Answer 32

-chemical reaction that converts CO2 and water ti glucose and oxygen

Question 33

Chemical equilibrium

Answer 33

rate of formation of products is the same as the rate of breakdown of products (formation of reactants) -no net change in concentration of reactants and products

Question 34

Completion

Answer 34

all reactants are converted to products