Year 9 Yearly Mistakes Flashcards

Question

Why is it called Alkaline Earth Metals?

Answer 1

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

Answer 2

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

Answer 3

Lithium, sodium and potassium

Answer 4

Beryllium, Magnesium and Calcium

Answer 5

Fluorine, Chlorine and Bromine

Answer 6

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

Answer 7

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

Answer 8

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

Answer 9

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.

Answer 10

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

Answer 11

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

Answer 12

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.

Answer 13

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

Answer 14

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.

Answer 15

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.

Answer 16

An organism that kills and eats other animals

Answer 17

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

Answer 18

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.

Answer 19

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.

Answer 20

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.