Rare earth metals are a group of 17 elements - lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium, yttrium - that appear in low concentrations in the ground
Answer:
Metals:
Copper: to make cooking utensils such as pots because it has a high heat conductivity.
Aluminium: to make aluminium foil / soda cans because it is malleable
Mercury: fills up thermometers because it can indicate the temperature when it expands. But it is toxic so fewer people are using mercury thermometers now.
Titanium: to make the body of supersonic aircrafts because it is strong and corrosion resistant
Gold: to make jewelry because it is shiny and also corrosion resistant
Non-metals:
Nitrogen: to fill up chip packages because its molecules are unreactive
Helium: to fill up balloons because it is lightweight
Hydrogen: for generating electricity in hydrogen fuel cells. It is environmentally-friendly because it does not produce any greenhouse gas or toxic pollutants.
Fluorine: added in toothpaste for strengthening the teeth. It can also prevent cavities.
Carbon: the graphite in pencils. this is one form of carbon. Other common forms (allotropes) of carbon include diamond and Buckminsterfullerene (buckyball).
Answer:
The reaction that occurs is a redox reaction. The Copper metal (Cu 0)on the copper pennies is oxidized in concentrated nitric acid to produce Cu2+ ions. Copper is easily oxidized to Cu2+, which is blue in aqueous solutions (water) so you should see the solution turn blue as the copper penny reacts.
Have a nice day ;)(^-^)