Chemistry Y9 T2 Flashcards
Extra (74 cards)
1
Q
atom
A
The smallest particle
of an element
2
Q
atomic number
A
The number of protons
in an atom
3
Q
charge
A
An electric property of matter
4
Q
electron
A
A very small subatomic
particle with negative charge
5
Q
electron cloud model
A
A model of the atom in which electrons move freely
6
Q
element
A
A substance made up of only one type of atom
7
Q
ion
A
An atom or molecule with
a net charge
8
Q
isotope
A
A variation of an element
with a certain number of
neutrons in each atom
9
Q
mass number
A
The number of protons and neutrons in an atom
10
Q
molecule
A
A group of atoms bonded together
11
Q
negative ion
A
An atom or molecule with a net negative charge
12
Q
net charge
A
The overall electrical charge
of a particle
13
Q
neutral particle
A
A particle with zero
net charge
14
Q
neutron
A
A large subatomic particle
with no charge
15
Q
nucleus
A
The central part of an
atom, with an overall
positive charge
16
Q
planetary model
A
A model of the atom in
which electrons move in
defined orbits
17
Q
positive ion
A
An atom or molecule with a net positive charge
18
Q
proton
A
A large subatomic particle
with positive charge
19
Q
radiation
A
The energy or particles
released during radioactive decay
20
Q
radioactive decay
A
The process of unstable
atoms releasing radiation
21
Q
stable isotope
A
An isotope in which the
nucleus is not likely to
break apart
22
Q
subatomic particle
A
A particle of matter that is
smaller than an atom
23
Q
unstable isotope
A
An isotope in which
the nucleus is likely to
break apart
24
Q
What is a chemical reaction?
A
A change in matter that forms 1 or more new substances
25
Physical Change Examples
Change is position, shape, size, state.
26
Chemical Change Examples
Release of sound, formation of gas, change in colour, disapearance of a solid, creation of a solid, change in temperature.
27
Chemical Bond
An attractive force that holds two atoms together.
28
Compound
Two or more different types of atoms bonded together.
29
General Equation for combustion reactions
fuel + oxygen → other products + energy
30
How is an electrically neutral atoms formed?
Where there is an equal number of protons and electrons, then the positive and neutral charges balance each other out.
31
Why do electrons not need to be considered when comparing the masses of atoms?
The mass of an electron is so small that it is insignificant compared to the mass of protons and neutrons
32
Why do the heavier isotopes of an element become unstable and break down into simpler atoms?
The heavier isotopes break apart from having too many neutrons as too much mass or energy creates unstable atoms. They atoms then release particles or energy (readioactive decay)
33
What do symbol equations show that word equations don't?
They show us which substances contain which elements and the relative amount of each element in the compound.
34
What is the meaning of the state symbols (s), (l) (aq), (g)
Solid, Liquid, Aqueous, Gas
35
What does the law of conversions of matter state?
The law of conversion states that matter cannot be created or destroyed in a chemical reaction.
36
What does the different numbers of neutrons change about different isatopes physically.
Melting point (the temperature it melts)
Density (how much mass is in a given volume)
37
Describe the properties of acids.
Sour taste, corrosive, reacts with metal, solution of a compound disolved in water
38
Describe the properties of bases.
They can be solid or liquid,
some solid bases can be dissolved in water (alkali) they have a soapy, slippery feel, they have a bitter taste, corrosive
39
An alkali is:
a base in a solution or one that can be dissolve
40
Acids release:
Bases release:
hydrogen ions (H+) in solution
hydroxide ions (OH–)
41
Amount of hydrogen and hydroxide ions needed to make acids, neutral substances and bases.
Acids- higher concentration of hydrogen ions than hydroxide ions
Neutral- same concentration of hydrogen and hydroxide ions
Base- more concentration of hydroxide ions than hydrogen ions.
42
Meaning of pH.
Power Hydrogen
43
What does the pH scale measure
The concentration of hydrogen ions in a substance
44
Over the past 250 years acid levels in the ocean have increased by:
25-30%
45
Corrosion
Slow reaction where metals react with oxygen. (eg. rust)
46
incomplete combustion produces:
carbon (soot), which is dirty, and carbon monoxide, which is poisonous
47
complete combustion produces:
carbon dioxide. It's a greenhouse gas that captures heat, warming the planet. It also forms an acid in water, posing serious problems for the oceans
48
Sulfur impurities in coal and oil burn to produce:
sulfur dioxide (SO2), a gas. It dissolves in rain water making sulfuric acid – acid rain which destroys forests and pollutes waterways
49
nitrogen dioxide (NO2) from engines contributes to:
acid rain
50
Where do tress and other plants get a lot of their mass from?
Carbon Dioxide in the air
51
Two main stages of photosynthesis equation
1. Light energy splits water to form oxygen and hydrogen
2. The hydrogen combines with carbon dioxide to form glucose, a simple sugar made up of carbon, hydrogen and oxygen
52
Word and symbol equation of photosynthesis
Carbon dioxide + Water + Sunlight → glucose + Oxygen
6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂
53
Word and symbol equation of respiration
1. glucose + oxygen → carbon dioxide + water
2.C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + energy
54
What is the relationship between respiration and breathing?
Breathing makes respiration possible by supplying oxygen from the air and getting rid of the carbon dioxide produced
55
What caused the great oxigenisaton event.
Cyanobacteria (microscopic organisms) began to carry out photosynthesis
56
Explain the difference between ionizing and non-ionizing radiation.
Ionizing removes electrons from atoms making them positive ions. It can also remove DNA which can lead to cancer and other disease.
57
Types of electromagnetic radiation.
gamma rays, x-ray, microwave, infrared, ultraviolet, radio waves, visible light
58
Types of particle radiation and their charecteristics.
Alpha- 2 protons 2 neutrons, big size so low travelers.
Bata- Make of very small electrons travel very fast but not as speed of light.
59
Key things about EM waves.
- have no mass
- have no charge
- travel at the speed of light in vacuum
-either ionizing or non-ionizing
60
Alpha and beta particles are both produced by
Nuclear reactions
61
What is a mixture?
A combination of substances that can be physically seperated.
62
Acids and bases in a chemical reaction combined form?
Water and salt
63
Acids and a base that is carbonate combined form?
Water, salt and carbon dioxide
64
How much of the produced carbon dioxide goes into the oceans?
About 30%
65
What do complete combustion reactions produce and what do incomplete combustion reactions produce and
Complete: Carbon dioxide, water vapor
Incomplete: carbon monoxide (CO), carbon (C), and less CO₂ + water vapor
66
Equation of carbonate as a base.
acid + carbonate → water + salt +carbondioxide
67
What is the process that releases hydrogen into the ocean.
1. Carbon dioxide + water → carbonic acid
2. carbonic acid → bicarbonate hydrogen ion
68
example of acids, bases and neutral substances
Acids- vinigar, lemon juice, milk
Base- stomach acid, baking soda, soap, bleach, seawater
Neutral- distilled water
69
what is a mixutre?
a solution that is not chemically reacted and can be physically separated.
70
what is a solution?
Substances that are chemically reacted and cannot me physically seperated
71
Difference between corrosive and caustic?
Corrosion and caustic both damage/destroy things they touch but caustic is meant to for bases whereas corrosion is for both.
72
Properties of neutral substances:
-not corrosive
-sweet/salty/no taste
-pH of 7
73
What are hydrocarbons and Eg's.
Hydrocarbons is hydrogen and carbon atoms that produce carbon dioxide in a combustion reaction producing carbon dioxide, water and energy.
74
Difference between exothermic and endothermic ad examples.
Exothermic gives off head Eg. Radiation
Endothermic takes in heat Eg. Photosynthesis.
