Year 9 Yearly Mistakes

Question 1

Define ecosystem

Answer 1

The biological community of organisms and their physical environment

Question 2

Define precipitation

Answer 2

Any product of the condensation of atmospheric water vapour that falls under gravitational pull from clouds.

Question 3

Define infiltration

Answer 3

The process by which water on the ground surface enters the soil

Question 4

Define respiration process

Answer 4

The carbon in glucose is released back into the atmosphere as carbon dioxide

Question 5

Name of Process that allows nitrogen to be used by living organisms

Answer 5

Nitrogen fixation

Question 6

When does nitrogen fixation occur?

Answer 6

Mostly in lightning strikes

Question 7

How do lightning strikes do this?

Answer 7

The electrical energy from a storm converts atmospheric nitrogen into various useful nitrogen compounds.

Question 8

Define decomposers

Answer 8

Organisms that use the organic matter of dead plants and animals

Question 9

Define nucleic acids

Answer 9

The building blocks of genetic material

Question 10

Define biodiversity

Answer 10

The variety of plants and animals and other living things in a particular area or region

Question 11

Define competitors

Answer 11

Organisms that require the same resources from the same habitat.

Question 12

Define conservation

Answer 12

Preservation of natural resources for future generations.

Question 13

Define ecology

Answer 13

Study of the relations of organisms to one another and to their surroundings.

Question 14

Define prey

Answer 14

An organism that is used as food.

Question 15

Define sustainable

Answer 15

Not being harmful to the environment or depleting natural resources, and therefore supporting long-term ecological balance.

Question 16

Why are elements containing 1 or 7 valence electrons highly reactive?

Answer 16

An element containing 1 or 7 valence electrons is highly reactive as the closer an element is to noble gas configuration, the more reactive it is.

Question 17

How does an element containing 1 valence electron get to noble gas configuration?

Answer 17

By either subtracting an electron or adding 7 valence electrons.

Question 18

How do the vertical (up/down) trends relate to the size of an atom?

Answer 18

When you travel downwards, the element has more electron shells meaning that the atom is larger than the element above it and smaller than the element below it.

Question 19

Define atom

Answer 19

The smallest particle of an element that has all of the chemical properties of that element.

Question 20

Define matter

Answer 20

Physical substances made of atoms. It has weight and takes up space.

Question 21

Define scientific model

Answer 21

A scientific model is a simplified representation or approximation containing the basic and most important parts of a real system, used to show how the real system works or can be changed.

Question 22

Define periodic table

Answer 22

A table of the chemical elements arranged in order of atomic number, usually in rows, so that elements with similar atomic structure (and hence similar chemical
properties) appear in vertical columns.

Question 23

Define radioactive

Answer 23

A substance containing unstable atoms, which can spontaneously decay (break down) and emit nuclear radiation, either alpha or beta particles or gamma rays.

Question 24

Define radioisotope

Answer 24

An isotope of an element that is unstable (and thus radioactive).

Question 25

Why is it called Alkaline Earth Metals?

Answer 25

Named after their oxides, the alkaline earths. These oxides are basic (alkaline) when combined with water.

Question 26

Why is it called Alkali Metals?

Answer 26

The alkali metals are so named because when they react with water they form alkalies.

Question 27

Name 3 elements from Group 1

Answer 27

Lithium, sodium and potassium

Question 28

Name 3 elements from Group 2

Answer 28

Beryllium, Magnesium and Calcium

Question 29

Name 3 elements from Group 17

Answer 29

Fluorine, Chlorine and Bromine

Question 30

Examples of carbon’s existence

Answer 30

Carbon dioxide gas in the atmosphere, fossil fuels, organic matter, dead organisms, pollution and in the ocean.

Question 31

Methods of distributing carbon atoms among organisms in an ecosystem

Answer 31

Photosynthesis and digestion distribute carbon atoms among the organisms within an ecosystem.

Question 32

Provide an example of nitrogen importance

Answer 32

Nitrogen plays an essential part in the formation of amino acids and nucleic acids.

Question 33

How is nitrogen returned to the ecosystem?

Answer 33

Nitrogen is returned to the ecosystem as ammonia (chemical formula NH3), present in urine and faeces, or when dead organic matter decomposes. This ammonia is converted back into nitrates by nitrifying bacteria that are naturally present in the soil. Another type of bacteria, the denitrifying bacteria, converts these nitrates back into atmospheric nitrogen gas.

Question 34

What are autotrophs?

Answer 34

These are the organisms that can prepare their own food from simple substances like carbon dioxide and water.

Question 35

What does an energy pyramid show?

Answer 35

It shows the total energy in trophic levels and how that energy is lost along a food chain.

Question 36

Describe the appearance of energy pyramids

Answer 36

The base of the pyramid represents the energy contained in producers. The next level shows the energy contained in 1st order consumers and so on.

Question 37

Define human impacts

Answer 37

Any human activities which have a negative effect, either directly or indirectly, on either the biotic or abiotic components of an environment.

Question 38

Why is it named the greenhouse effect?

Answer 38

The glass which the greenhouse is made of allows light to enter and prevents heat from escaping, making it very warm inside. The heat allows the plants to grow in winter. A similar effect is happening to Earth.

Question 39

How is CO2 produced?

Answer 39

Carbon dioxide (CO2) is released in large quantities from natural processes including respiration by living organisms, volcanoes and forest fires. Man-made CO2 emissions are released into the atmosphere via power stations, motor vehicles and factory emissions.

Question 40

Define predator

Answer 40

An organism that kills and eats other animals

Question 41

Why is it called Halogens?

Answer 41

Because they all produce sodium salts of similar properties and Hal is salt in Greek while Gen means produce.

Question 42

Provide 3 examples of how radiation is used in depth

Answer 42

Radioactive isotopes like technetium-99m can be attached to certain chemicals called tracers, which are injected into the bloodstream and then accumulate in particular parts of the body. The radioactive isotopes emit radiation which can be picked up by a detector. It is used to diagnose bone, heart, kidney, lung, and blood flow problems.

Iodine-123 emits gamma rays with a half-life of about 13 hours. This means it is ideal for nuclear imaging of the thyroid. Iodine-123 is ingested or injected, and one day later a scan is done to visualise the amount of remaining iodine-123.Like technetium-99m, a gamma camera is used to detect the gamma rays emitted from the isotope to test whether the patient has thyroid cancer or not.

Sodium-24 is used as a radioactive tracer to detect leaks in pipes. Leaks in underground pipes may be difficult to find. A small amount of a radioisotope is added to the pipe, and then a detector is moved along the ground above the pipe. The amount of radiation detected will increase near a leak, because the amount of liquid containing the tracer is higher where it is leaking out of the pipe into the ground. If you then move beyond the leak, the amount of radiation coming from the pipe will decrease because some of it has leaked out.

Question 43

How did Dalton discover compounds?

Answer 43

He carefully examined the experiments of others (and repeated a few) and realised that elements seemed to join in very fixed ratios, as if 1 ‘part’ of an element always connected to 2 (or 3 or 4) parts of another element.

Question 44

What was Bohr’s theory?

Answer 44

According to Bohr’s atomic model, electrons move in definite orbits around the nucleus, much like planets circle the sun. These orbits, or energy levels, are located at certain distances from the nucleus.

Question 45

If Nitrates are NO3, then what is ammonia?

Answer 45

NH3

Question 46

If Nitrates are NO3, then what is ammonium?

Answer 46

NH4