Biology Chapter 2

Question 0

Atomic theory

Answer 0

The concept of an atom

Born in Ancient Greece (~500bc)

Question 1

Chemical basis of life

Answer 1

Atoms, molecules, and properties of H2O

Question 2

Atomic structure

Answer 2

The nature of an atom

Proton, neutron, electron, ion, isotopes

Question 3

Atomos

Answer 3

All matter is made up of tiny invisible particles named

Question 4

Matter

Answer 4

Has mass and occupies space

Question 5

Matter is

Answer 5

Composed of chemical elements.

Gas, solid, liquid, plasma

Question 6

Element

Answer 6

Has atomic characteristics and cannot be broken down into other substances

Question 7

Atom

Answer 7

Smallest unit of matter with retains the chemical and physical properties of an element

Question 8

Proton
Electron
Neutron

Answer 8

Positive
Negative
No charge

Question 9

Atomic structure

Answer 9

Nucleus composed of protons and neutrons and surrounded by orbiting electrons. Protons and neutrons have roughly the same mass (1 dalton)

Question 10

Atomic number

Answer 10

Same as number of protons

Question 11

Atomic mass and weight

Answer 11

Mass of protons and neutrons combined

Question 12

All atoms of an element have?

Answer 12

The same atomic number and mass

Question 13

In a neutral atom?

Answer 13

Number of protons = number of electrons

Question 14

Isotopes

Answer 14

Atoms must have a certain # of protons to retain the characteristics of a given element, but # of neutrons sometimes vary.
Unstable and decay at constant rate

Question 15

Electrons

Answer 15

Orbit around nucleus (drawn by protons + charge)

Question 16

Valence 
# in valence dictates what?

Answer 16

Outermost shell

The reactivity of the atom

Question 17

Atoms will?

Answer 17

Accept, donate, or share electrons with other atoms to fill the valence shell and become stable.

Question 18

Chemical bonds

Answer 18

Attractive forces between atoms that result from accepting, donating, or sharing electrons.

Question 19

Bonding capacity?

Answer 19

of bonds atom will form

Question 20

Octet rule

Answer 20

Valence she’ll is full when it contains 8 electrons ( most stable)

Question 21

Molecule

Answer 21

2 or more atoms held together by chemical bonds (NaCL, H2)

Question 22

Compound

Answer 22

Substance composed of 2 or more different atoms (NaCL)

Question 23

Ions

Answer 23

Atoms in which the number of electrons doesn’t equal that of protons

Question 24

Cation

Answer 24

Atom which loses electron is now positively charged

Question 25

Anion

Answer 25

Atom which gains electron is now negatively charged

Question 26

Types of chemical bonds

Answer 26

``` Ionic bonds Covalent bonds Polar covalent bonds Hydrogen bonds Non polar covalent bonds ```

Question 27

Ionic bonds

Answer 27

Complete transfer of electrons | Atoms held together by electrostatic attraction between oppositely charged cation and anion

Question 28

Ionic bonding

Answer 28

Resulting in compound neutral | Bonds are weak

Question 29

Covalent bonds

Answer 29

Chemical bond formed Between 2 atoms by the sharing of electrons Strength of bond increases with the # of shared electrons

Question 30

Polar covalent bonds

Answer 30

One atom of a molecule attracts electron more strongly than other atom (unequal sharing)

Question 31

Hydrogen bond

Answer 31

Occurs when + hydrogen atom of 1 polar molecule is attracted to the - atom of another polar molecule Occurs in DNA and protein

Question 32

Water

Answer 32

75% earth made up of | Vertebrates composed up to 66% water

Question 33

Unique properties of water

Answer 33

Polar molecule | Molecules bound to each other by hydrogen bonds

Question 34

Why water is unique

Answer 34

Extremely high specific heat Ice formation Cohesion High polarity

Question 35

Ice formation

Answer 35

H+ bonds in water form a crystal lattice which traps air | Causes solid water to be less dense than liquid (ice)

Question 36

Cohesion

Answer 36

Attraction of water molecules to each other. Surface tension caused by cohesion

Question 37

Adhesion

Answer 37

Attraction of water molecules to polar molecules

Question 38

High polarity

Answer 38

``` Polar hydrophilic (water loving) molecules are highly soluble in water Non polar hydrophobic molecules are soluble in water (oils) ```

Question 39

pH

Answer 39

Is the potential hydrogen of a substance pH of pure water is 1 dalton or 1 H+ per liter of water pH scale on 0-14 pH 0-6.9 is acidic Readily dissociate in water and donate H+ ions Adding H+ ions decreases pH

Question 40

Buffers

Answer 40

Accept or donate H+ ions | Carbonic acid buffers the pH of the blood