Chemical Basis of Life

Question 1

Element

Answer 1

A substance that cannot be broken down by any chemical means

Question 2

Matter

Answer 2

Anything that occupies space and has mass

Question 3

Compound

Answer 3

A substance consisting of 2 or more different elements combined in a fixed ratio

Question 4

Name 2 examples of a compound

Answer 4

Water, Salt

Question 5

Trace element

Answer 5

essential for life but required in extremely small amounts

Question 6

Name 3 examples of trace elements

Answer 6

Sodium, Sulfur, Chlorine

Question 7

Atom

Answer 7

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

Question 8

Proton

Answer 8

Positive

Question 9

Nuetron

Answer 9

nuetral

Question 10

Electron

Answer 10

Negative

Question 11

Nucleus

Answer 11

An atoms central core, containing only protons and nuetrons

Question 12

Atomic Number

Answer 12

The number of protons in the nucleus

Question 13

Mass number

Answer 13

The sum of protons and neutrons in the nucleus

Question 14

Atomic mass

Answer 14

Total mass of an atom; approx. mass number

Question 15

Isotope

Answer 15

One of the atomic forms of an element, each with the same number or protons but different number of nuetrons

Question 16

Radioactive Isotope

Answer 16

The nucleus decays spontaneously giving off particles and energy

Question 17

What are the six most common elements in living things

Answer 17

Carbon, phosphorus, oxygen, nitrogen, sulfur, hydrogen

Question 18

Compare and contrast the difference between ionic and covealent bonds

Answer 18

Ionic bonds result when electrons are transferred between atoms. Covalent bonds result when valence electrons are shared between atoms.

Question 19

Molecule

Answer 19

2 or more atoms held together by covalent bonds

Question 20

Electonegativity

Answer 20

Determines the measure of how much attraction atoms have toward another atom. For example, oxygen has more electronegativity than hydrogen resulting in it being positive.

Question 21

Non polar Covalent bond

Answer 21

A covalent bond in which electrons are shared equally between two atoms of similar electronegativity

Question 22

Polar Covalent bond

Answer 22

A covalent bond between atoms that differ in electronegativity. The shared electron is pulled closer to the more electronegative atom, making it slightly negative and the other slightly positive.

Question 23

Polar Molecule

Answer 23

A molecule containing polar covalent bonds and having an uneven distribution of charges

Question 24

Ion

Answer 24

An atom or group of atoms that has gained or lost 1 or more electrons, thus acquiring a change

Question 25

Ionic Bond

Answer 25

aA chemical bond resulting from the attraction between oppositely charged ions

Question 26

Salt

Answer 26

A compound resulting from the formation of ionic bonds, also called an ionic compound

Question 27

Hydrogen bond

Answer 27

A type of weak chemical bond formed by a positive bond attracted to a negative bond

Question 28

Chemical reaction

Answer 28

The making and breaking of chemical bonds, leading to changes in the composition of matter

Question 29

Reactants

Answer 29

A starting material in a chemical reaction

Question 30

Product

Answer 30

An ending material in a chemical reaction

Question 31

Cohesion

Answer 31

The sticking together of molecules of the same kind, often by hydrogen bonds. Water sticking to itself

Question 32

Adhesion

Answer 32

The attraction between different kinds of molecules. Water sticking to other things, this makes bubbles on a door or on plants, etc.

Question 33

Surface Tension

Answer 33

A measure of how difficult it is to stretch or break the surface of a liquid.

Question 34

Give an example of a bond that has high surface tension

Answer 34

Water because the hydrogen bonding of its surface molecules

Question 35

Heat

Answer 35

Thermal Energy: The amount of energy associated with the movement of the atoms and molecules in a body of matter

Question 36

Temperature

Answer 36

A measure of the intensity of heat in degrees, reflecting the average kinetic energy.

Question 37

Evaporative cooling

Answer 37

The process in which the surface of an object becomes cooler during evaporation.

Question 38

Which is more dense: Water or Ice

Answer 38

Water

Question 39

What is an aqueous solution

Answer 39

A solution in which water is the solvent

Question 40

Solute

Answer 40

the substance being dissolved

Question 41

Solvent

Answer 41

the substance that is dissolving a solute

Question 42

Describe the buffer system

Answer 42

In blood vessels, lungs, etc. there are both acid and base fluids that are in equilibrium. When a hydrogen ion is added, this will decrease the acid level, so the base will become an acid for a short period of time in order to keep the same Ph level. The same goes for if a hydrogen ion was lost, it would raise the acid level, so an acid would change into a base to stay equal.

Question 43

Explain Acid precipitation

Answer 43

Acid precipitation is rain that is below 5.6 ph. it is formed when fossil fuels are burned making nitrogen and sulfur which combine with water to make acid rain