Chemical Basis of Life

Question 1

Nucleus

Answer 1

is made up of a proton, a positive charge, and a neutron, which has no charge

Question 2

Electrons

Answer 2

negative charge

Question 3

What does each shell/energy level have?

Answer 3

Anything ≥2 electrons, protons equal to electrons

Question 4

Outermost shell/energy level

Answer 4

valence shell and it contains the chemically reactive electrons.

Question 5

Matter

Answer 5

anything that occupies space & has mass

Question 6

Atom

Answer 6

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

Question 7

Element

Answer 7

A substance that cannot be broken down into other substances (normally)

Question 8

Molecule

Answer 8

group of ≥2 atoms bonded together. e.g h2

Question 9

Compound

Answer 9

molecule containing ≥2 elements in a fixed ratio e.g. CHO, NaCL, H20

Question 10

Mixture

Answer 10

≥2 elements mixed in varying ratios. Bonds may not form. e.g. sucrose and calcium

Question 11

Solution

Answer 11

A liquid homogenous mixture of ≥2 elements

Question 12

What is a solution made of?

Answer 12

Solvent, dissolving agent. Solute, the substance that is dissolved

Question 13

Atomic number

Answer 13

Number of protons

Question 14

Mass number(atomic mass)

Answer 14

sum of protons and neutrons

Question 15

Radioactive Isotope(radioisotope)

Answer 15

An isotope w/ an unstable nucleus, decays, & emits enrgy & particles(+,0,-)

Question 16

Isotope

Answer 16

A variant form of an element. contains a variant number of neutrons e.g. 12^C, 13^C, 14^C

Question 17

Ion

Answer 17

An atom that has gained or lost an electron, therefore has a net positive or negative charge. Na+, Cl-

Question 18

Octet rule(ruleof eights)

Answer 18

atoms are reactive until they have 8 electrons in their valence shell, form bonds

Question 19

What will not form bonds?

Answer 19

atoms with their valence shells filled making them stable/inert

Question 20

Ionic Bonds

Answer 20

Electrons are accepted or donated. the product is called an ion.

Question 21

What are atoms that give up an electron called

Answer 21

Cations and have a net positive charge

Question 22

What a atoms that accept an electron called

Answer 22

Anions and have a net negative charge

Question 23

Covalent bonds

Answer 23

electron pairs are shared e.g. H2= H-H (1 pair shared), O2= O=O (2 pairs shared), N2= N ☰ N

Question 24

Nonpolar

Answer 24

both atoms exert equal pull on the shared electrons e.g. H2

Question 25

Polar

Answer 25

One atoms exerts more pull on the shared elctrons due to its extra proton(s) e.g. H2O H-O-H

Question 26

Hydrogen bonds

Answer 26

the slightly (+) H in a polar molecule forms a weak bond (especially @ body temp) w/ N & O. No electrons are actually shared. e.g., bonding in water, tertiary structure in proteins

Question 27

Reactants

Answer 27

Chemicals being changed by a reaction EX. [Na+Cl]-> NaCl

Question 28

Products

Answer 28

Chemicals produced by a reaction EX. Na+Cl-> [NaCl]

Question 29

Synthesis

Answer 29

Production of a more complex molecule than either of the reactants. Occurs during anabolic physiological processes. EX. Na+Cl-> NaCl

Question 30

Decomposition

Answer 30

Product is a less complex molecule than either reactant. Occur during catabolic physiological processes. NaCl-> Na+ + Cl-

Question 31

Exchange

Answer 31

Parts of 2 different molecules exchange position e.g. acid & base reacting to produce salt & water. AB + CD -> AD + CB

Question 32

Reversible Reaction

Answer 32

Products can change back to the reactant & vice versa. NaCl<-> Na+ + Cl-

Question 33

Catalyst

Answer 33

Molecule that increases the rate of reactions (but are not consumed by it)

Question 34

Electrolytes

Answer 34

substances that release ions in water ex. NaCl + H2O -> Na+ +Cl +H2O

Question 35

Acid

Answer 35

Electrolytes that release H+ ions ex. HCl

Question 36

Base(alkali)

Answer 36

Electrolytes that accepts H+ ions ex. NaOH

Question 37

Salt

Answer 37

Electrolyte formed by the reaction of a acid & a base ex. HCl + NaOH -> H2O +Na CL

Question 38

Buffer

Answer 38

Substance that resists changes in pH by accepting or donating H+ ions

Question 39

pH Scale

Answer 39

Measurement of the H+ ion/ OH- concentration. (0-14; each unit a 10x change) pH distilled water/blood= 7.0-*

Question 40

How much iodine do humans need in a day?

Answer 40

0.15 mg or goiters develop