Ch. 2 - Chemical Context of Life

Question 1

matter

Answer 1

Takes up space and has mass. Affected by gravity

Question 2

element

Answer 2

pure substance, can’t be broken down into different substances

Question 3

elements are made up of

Answer 3

atoms

Question 4

Trace element

Answer 4

we only need them in small quantities (zinc, iron)

Question 5

elements of life

Answer 5

we need them to survive.

25 total, but 4 make up 96% of all living matter

Question 6

compound

Answer 6

A substance consisting of two or more elements combined in a fixed ratio (H20)

Question 7

four essential elements make up 96% of all living matter

Answer 7

a. Oxygen
b. Carbon
c. Hydrogen
d. nitrogen

Question 8

If there is a deficiency of an essential element ______ happens

Answer 8

disease

Question 9

Subatomic particles

Answer 9

neutron, proton, electron

Question 10

neutron

Answer 10

neutral charge

Question 11

proton

Answer 11

+ charge

Question 12

electron

Answer 12

• charge

Question 13

atomic number

Answer 13

of protons in an atom

Question 14

True/False: Atoms have the same number of protons and electrons

Answer 14

Mostly true: when they are in their neutral state, which is their normal state

Question 15

Ion

Answer 15

An electrically charged atom (not in neural state). It does NOT have the same number of protons and electrons

Question 16

Atomic mass

Answer 16

Protons + neutrons = atomic mass

Question 17

Isotope

Answer 17

same number of protons but greater number of NEUTRONS than other samples of the same element, so it has greater mass

It can spontaneously turn radioactive.

Question 18

Example of isotopes

Answer 18

Carbon-6, Carbon-12, Carbon 14

Question 19

Electron shells

Answer 19

represent the average distance from the nucleus and energy level of electrons circling the nucleus

Question 20

The ___ an electron is to/from the nucleus, the more energy it has

a) closer
b) further

Answer 20

further

Question 21

When an electron absorbs energy it becomes

Answer 21

excited

Question 22

Excited electrons move to _____ energy levels

Answer 22

higher

Question 23

When an electron loses energy

Answer 23

falls down energy levels towards the nucleus

Question 24

energy

Answer 24

capacity to cause change

Question 25

Potential energy

Answer 25

energy in matter due to location or structure higher locations= more potential energy more complex structures = more potential energy

Question 26

Kinetic energy

Answer 26

energy of motion

Question 27

The chemical behavior of an atom depends on

Answer 27

its electron configuration and distribution

Question 28

Valence electrons

Answer 28

electrons in the outermost shell (red) of valence electrons determines atom's chemical behaviors (shown in periodic table groups)

Question 29

Orbital

Answer 29

the three-dimensional space where an electron is found 90% of the time

Question 30

Covalent bonds (strong)

Answer 30

Between non-metals; they share valence electrons - Can be polar or non-polar

Question 31

Molecule

Answer 31

atoms joined by covalent bonds

Question 32

electronegativity

Answer 32

an electronegative atom pulls electrons of a covalent bond towards itself (Polar covalent bonds)

Question 33

Non-polar covalent bond

Answer 33

The electron is shared equally (O2, H2) Always between atoms of the same element

Question 34

Polar covalent bond

Answer 34

One atom is more electronegative than the other and pulls electrons towards itself The more to ---> in the periodic table, the more electronegative

Question 35

Anion

Answer 35

negatively charged ion (stole the electron in the bond)

Question 36

Cation

Answer 36

positively charged ion. Lost an electron

Question 37

Ionic bond (strong)

Answer 37

Formed between anions and cations (Na+Cl-) Metals and non-metals

Question 38

Ionic compounds almost always create

Answer 38

salts, made of crystals

Question 39

Two types of weak bonds

Answer 39

1) Hydrogen bonds 2) Van der Waals interactions

Question 40

Hydrogen bonds

Answer 40

between Hydrogen in a polar covalent bond (because the H is slightly +) and any neighboring negative charge.

Question 41

Van der Waals interactions

Answer 41

the weakest type of bonds, temporary Electrically charged outer shells of atoms/molecules nearby barely touch each other as they move around

Question 42

Why are weak bonds important?

Answer 42

They give shape to large molecules and help them adhere to each other

Question 43

Chemical bonds are made and broken in _______

Answer 43

chemical reactions that change the composition of matter

Question 44

The resulting substance(s) of a chemical reaction is the _______

Answer 44

product (s)

Question 45

Chemical reaction basic formula

Answer 45

reactant + reactant --> product

Question 46

when the forward and reverse reaction rates are equal in a chemical reaction

Answer 46

Chemical equilibrium (balanced equation)