Answer:
The false statement is :
- Pyrite is an ore of gold and is used in jewelry making.
- Cobalt is not used in medicine.
Explanation:
Pyrite is an ore of iron sulfide found on the Earth and in coal, limestone and in many deposits of metallic ores. Due to its luster and pale yellowish color it appears as gold due to which it is also termed as Fool's gold.
It is used in firearms , in production of sulfur dioxide gas, etc.
Cobalt is used as medicine to treat cancer patient. Co-60 is used in treatment of cancer in which gamma rays produced by Co-60 are used to kill tumor cells in a cancer patient.
Where as talc is used in industries like : paper making, food, paints, plastics etc. Quartz is primary material used to prepare glass and cobalt is used as
Answer:
C. Destructive interference
Explanation:
<em>Destructive interference</em> is when there are two waves <u>with the same frequency</u>, and the peaks of one wave (the highest points) line up with the valleys (the lowest points) of the second one.
Constructive interference would cause the sound to be louder.
Absorption and reflection are interactions that would not take into account the fact that the headphones produce sounds.
Answer:
Anthracite
Explanation:
Anthracite produce highest amount of energy than other. It contain 86-97 percent carbon. Bituminous coal contain 45-86 percent carbon.
Subbituminous cola have 35-45 percent carbon while lignite contain 25-35 percent carbon.
Coal is source of many organic materials. It is fossil fuel and form after long period decay of plants. It is formed when trees are buried under earth
about 500 million years ago. The chemical and bacterial reactions take place and plant wood converted into the peat.
Than because of high temperature and pressure inside the earth peat is converted into the coal.
Through other processes it is than used to make the fuels such as coke. coal tar and coal gas.
Coal tar is the source of many organic compounds which are separated through fractional distillation.
About 80% of coal in Pakistan is used to bake the bricks and also used in lime kilns and for domestic purpose.
Answer:
Group 2A (or IIA) of the periodic table are the alkaline earth metals: beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra). They are harder and less reactive than the alkali metals of Group 1A.
Explanation:
