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Topic Test Flashcards

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Biology 101 flashcards
1
Q

J.J. Thompson

A

Devised the plum pudding model. Shows negatively charged electrons embedded in a positively charged sphere.

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2
Q

Democritus

A

First suggested matter was made up of atoms, 2500 years ago

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3
Q

Current atom model

A

Nucleus is tiny and is made up of protons and neutrons, surrounded by electrons.

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4
Q

John Dalton

A

His theory proposed that all matter consisted of tiny particles called atoms. Atoms cant be divided into smaller particles, atoms of the same element are alike, atoms combined in one are called compounds

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5
Q

Lord Rutherford

A

His model was same as today except it proposed orbiting electrons would lose energy and would collide back into the nucleus.

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6
Q

Niels Bohr

A

Studied with Rutherford. Proposed different energy levels in electrons around nucleus. To go to different levels electron energy is gained or lost.

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7
Q

Sir James Chadwick

A

Discovered nucleus contained neutrons and proton. Neutrons have no charge.

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8
Q

Nucleus

A

Small, very dense. Contains neutrons and protons. Nucleus makes up almost all atom’s mass. Neutrons and protons held together by very strong nuclear force.

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9
Q

Protons

A

Found in nucleus. Has positive charge

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10
Q

Neutrons

A

Found in nucleus. Has no charge

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11
Q

Electrons

A

Orbit around nucleus. Path followed referred to as electron cloud. Have negative charge, number of electrons in atom is equal to number of protons in nucleus.

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12
Q

Atom

A

Makes up matter. Electrically neutral. Consists of protons, neutrons and electrons

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13
Q

Chemical reaction

A

Chemical reactions take place when bonds between atoms break down and new bonds are formed. Changes that can take place; temperature, colour, formation of gas or solid, odour.
Sometimes energy is required to start reaction (eg. Light, heat, electric current).

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14
Q

Product

A

New substance produced due to chemical reaction

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15
Q

Reactant

A

Original substance that makes a chemical reaction

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16
Q

Antoine-Laurent Lavoisier

A

His ideas led to the law of conservation of mass and law of constant proportions

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17
Q

Law of conservation of mass

A

States that matter can neither be created nor destroyed during a chemical reaction.

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18
Q

Law of constant proportions

A

States a compound always contains the same relative amounts of each elements

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19
Q

Isotopes

A

Atoms of the same element but that have a different mass.

See notes for isotope representation

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20
Q

stable atom

A

Proton and neutron in nucleus held together very strongly

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21
Q

Unstable atom

A

Neutrons and protons in nucleus aren’t held together strongly

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22
Q

Radiosotope

A

Isotope that is unstable

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23
Q

Natural radioactivity

A

Emitted from matter without energy being supplied to atom

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24
Q

Artificial radioactivity

A

Made by bombarding the atoms with sub-atomic particles like protons and neutrons

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25
Q

Nuclear radiation

A

Energy emitted by radioactive substance

26
Q

3 types of nuclear radiation

A

Alpha particles
Beta particles
Gamma rays

27
Q

Alpha particles

A

Most charged
Heaviest
Bends in magnetic field
Stopped by paper

28
Q

Beta particles

A 
More penetrating 
Stopped by aluminium 
Bend to left in magnetic field
Lighter
Negative charge
29
Q

Gamma radiation

A 
Stopped by lead
Goes furthest
Most penetrating
Not particle
Pure energy 
No charge
30
Q

Half life

A

Time taken for half of radioactivity to decay

31
Q

Nuclear reactor

A

Creates electricity by using radioactivity

32
Q

Exothermic reaction

A

Reaction which gives out energy

33
Q

Endothermic reaction

A

Reaction which absorbs energy

34
Q

Acid

A

Anything with a pH level under 7
Corrosive
Has sour taste
Prevents growth of microorganisms

35
Q

Corrosive

A

Eats away at solid substances

36
Q

Bases

A

Have a bitter taste
Slippery or soapy to touch
Some a very corrosive
Bases that can be dissolved are called alkalis

37
Q

Acid-base indicator

A

Substance used to tell wether a substance is an acid or base

38
Q

Litmus

A

Is an acid-base indicator
Turns red in acid
Turns blue in base

39
Q

Bromothymol

A

Is an acid-base indicator
Turns yellow in acid
Turns bluish-purple in a base.

40
Q

pH scale

A 
Used to describe how acidic or basic a substance is.
Numbers range from 0-14
0 is most acidic 
14 is most basic
7 is neutral
41
Q

Universal indicator

A

Mixture of indicators
Colours change as strength of acid and bases change.
Used to measure the pH

42
Q

Neutralisation

A

When acid and base mix it creates salt and water

43
Q

Acid rain

A

Rain that has a pH of 4.2-4.4
Consists of:
NO -> nitric acid
SO2 -> Sulfur is acid

44
Q

Artificial source of SO2 and NO

A

Fossil fuels
Electric power generation
Oil refineries

45
Q

Natural source of SO2 and NO

A

Volcano

46
Q

Negative acid rain effects on Marine life

A

Acid goes in soil then into lakes, rivers and oceans. At pH 5 eggs cant hatch. At pH 4 kills off adult fish and plants.

47
Q

Negative acid rain effects on land

A

Removes nutrients in soils affecting trees. Damages cells on leaves and affects the flow of water.

48
Q

Neutralise

A

To stop something from having an effect

49
Q

Indigestion

A

Caused when you eat too quickly or too much of the wrong food and contents of stomach increase in acidity.
Hydrochloric acid in stomach is under 1.5

50
Q

Result of mixing an acid and metal

A

Creates a salt and hydrogen

51
Q

Combustion reaction

A

Reaction which a substance reacts with oxygen to produce heat.

52
Q

Fuel

A

Substance reacting with oxygen in a combustion reaction

53
Q

Fossil fuels

A

Fuel made of remains of living things.

Are compounds of hydrogen and carbon called hydrocarbon

54
Q

Uses for combustion reactions

A 
Cooking (methane)
Powering car (octane)
Planes (kerosene)
Oxidation 
Making electricity (coal)
Respiration (glucose)
Powering a rocket (hydrogen)
55
Q

Respiration

A

Takes place in every cell of your body
Slow combustion reaction
Happens when glucose from digested food reacts with oxygen that you breathe in. Produces carbon dioxide.

56
Q

Radiometric dating

A

Can be used to determine age of rocks and fossils.
Usually uses Isotope carbon-14 as it has a half-life of 5700 years. Radiometric dating using carbon called radiocarbon dating.
All living things contain radiocarbon. When living things die the decaying radiocarbon is being replaced isn’t being replaced therefore age of fossil or rock can be measured.

57
Q

Radiocarbon

A

A small amount of carbon

58
Q

How nuclear reactors work

A

Uranium is converted into uranium dioxide and sealed into rods called fuel rods.
Fuel rods undergo fission reaction when neutrons are fired at radioactive uranium.
Causes uranium nuclei to split and form two new elements, releasing neutrons, radiation and heat.
Heat is used to heat water producing steam which spins turbines.

59
Q

Radiotherapy

A

Use of radioisotopes to kill cancer cells or prevent them from multiplying. Can be targeted to small area so surrounding tissue not damaged.

60
Q

Negative uses for radioactivity

A

Nuclear weapons
Malfunctioning nuclear reactors
Causes cancers
Damaging cells in living things.

Science (12 decks)

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