Water Definitions

Question 1

Hydrogen bond

Answer 1

the intermolecular force that forms when a slightly positive hydrogen atom in one polar molecule is attracted to a slightly negative atom of another polar molecule

Question 2

Polarity

Answer 2

the property of having positive and negative poles

Question 3

Intermolecular forces

Answer 3

forces of attraction or repulsion between neighboring particles(atoms, molecules or ions)

Question 4

Cohesion

Answer 4

the attractive force between similar molecules

Question 5

Adhesion

Answer 5

the attractive force between dissimilar molecules

Question 6

Surface tension

Answer 6

the property of the surface of a liquid that allows it to resist an external force due the cohesive nature of its molecules

Question 7

Transpiration

Answer 7

the loss of water from leaves by evaporation through the stomata

Question 8

Capillary action

Answer 8

the movement of a liquid through a narrow space as a result of cohesion, adhesion and surface tension(this force can exceed the pull of gravity and cause liquids like water to move upwards)

Question 9

Solubility

Answer 9

the ability of a substance(the solute) to form a solution(dissolve) with another substance(the solvent)

Question 10

Solution

Answer 10

the mixture of a dissolved solute and a solvent

Question 11

Solute

Answer 11

the minor component in a solution dissolved in the solvent

Question 12

Solvent

Answer 12

the liquid in which a solute is dissolved to form a solution

Question 13

Hydrophillic

Answer 13

capable of interacting with water through hydrogen bonds

Question 14

Hydrophobic

Answer 14

incapable of freely interacting or dissolving in water

Question 15

Enzyme

Answer 15

proteins that act as biological catalysts in cells and allow chemical reactions to occur at a suitable rate in the conditions found in living organisms

Question 16

Density

Answer 16

the mass per unit volume of a substance

Question 17

Specific heat capacity

Answer 17

a measure of the energy required to raise the temperature of 1 kilogram of a substance by 1°C

Question 18

Thermal conductivity

Answer 18

the ability of a substance to conduct heat

Question 19

Buoyancy

Answer 19

the ability of an object to float on water

Question 20

Viscosity

Answer 20

the resistance of a fluid to flow

Question 21

Acid

Answer 21

a substance that can donate one or more protons and so become negatively charged(deoxyribonucleid acid(DNA))

Question 22

Atom

Answer 22

a unit of matter with positively charged protons grouped in the nucleus and negatively charged electrons in orbitals around the nucleus

Question 23

Base

Answer 23

a substance that can accept one or more protons(H⁺) and so become positively charged(e.g. adenine)

Question 24

Catalyst

Answer 24

a substance that increases the rate of a reaction but is by itself unchanged at the end of the reaction

Question 25

Concentration

Answer 25

the amount of substance per unit volume

Question 26

Condensation reaction

Answer 26

a reaction in which two molecules are combined into one molecule and water is eliminated

Question 27

Hydrolysis

Answer 27

the separation of one molecule into two using hydrogen(H) and hydroxyl group(OH) released by splitting a water molecule

Question 28

Intramolecular force

Answer 28

a bond between atoms within a molecule

Question 29

Isotope

Answer 29

one of the two or more alternative forms of an element, with the same number of protons and electrons, but a different number of neutrons

Question 30

Macromolecule

Answer 30

a molecule with a molecular mass of more than 10,000

Question 31

Molecule

Answer 31

two or more atoms joined together by one or more covalent bonds

Question 32

Oxidation

Answer 32

a reaction in which hydrogen is removed, electrons are removed, or oxygen is added

Question 33

Reduction

Answer 33

a reaction in which hydrogen is added, electrons are added, or oxygen is removed

Question 34

Pigment

Answer 34

a substance that absorbs wavelengths of visible light and so appears coloured

Question 35

Polymer

Answer 35

a molecule consisting of a series of many subunits linked by covalent bonds

Question 36

Radioactive

Answer 36

referring to a type of isotope with an unstable nucleus which can emit radiation(α, β, γ rays)

Question 37

Synthesis

Answer 37

the production of more complex molecules from simpler substances by one or more chemical reactions

Question 38

Movement

Answer 38

an action by an organism or part of an organism causing a change of position or place

Question 39

Respiration

Answer 39

The chemical reactions in cells that break down nutrient molecules and release energy for metabolism

Question 40

Sensitivity

Answer 40

The ability to detect or sense stimuli in the internal or external environment and to make appropriate responses

Question 41

Homeostasis

Answer 41

the maintenance of a constant internal environment

Question 42

Growth

Answer 42

A permanent increase in size or dry mass by an increase in cell size or cell number or both

Question 43

Reproduction

Answer 43

The processes that make more of the same kind of organism

Question 44

Excretion

Answer 44

The removal of the waste products of metabolism, toxic materials and substances in excess of requirements from organisms

Question 45

Nutrition

Answer 45

the taking in of materials for energy, growth, and development