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:
B: electronegativity
Explanation:
Electronegativity is the measure of how strongly atoms attract bonding electrons to themselves.
A is incorrect because Atomic radius though decreases as you go from lithium to fluorine of the periodic table. Atomic radius increases when you go from either top to bottom of the periodic table, or if you go from right to left. So answer A is inaccurate.
C is incorrect because in period 2, all the elements have two electron subshells. For example, Al has 13 electrons. So it has two electron subshells. This is since the first subshell has only two valence electrons and while the second subshell in Al has 11 valence electrons. Therefore, it is inaccurate to say this answer.
D is incorrect because in the first shell, you can only have a max of two electrons. The first shell neither decreases or increases. Therefore, D is inaccurate too.
B is correct because as you go from the periodic table from left to right, the electronegativity and ionization energy increases. This is since the more valence electrons an element has, the more electronegative is. Fluorine for example is desperately trying to get one more electron to have a total of 8 electrons. It wants to have a full shell. Therefore, B is the most relevant answer.
Each type of
mineral has a chemical composition that is unique such as its chemical composition
and the arrangement of atoms. For example, the mineral hematite is Fe2O3. There
are two atoms of iron (Fe) and three atoms of oxygen (O).
Answer
Atomic number or proton number tells us the number of protons found in the nucleus of every atom of that element
Explanation:
The answer is C, <span>Many chemicals are dangerous </span>
