The answer would 5.66 x 10 power of 24
Yes
Methane also is the chief constituent of natural gas, which contains from 50 to 90 percent methane (depending on the source), and occurs as a component of firedamp (flammable gas) along coal seams.
Answer:- B:
is the right answer.
Solution:- The balanced equation is:

We have been given with 8.75 grams of oxygen and asked to calculate the grams of hydrogen needed to react with given grams of oxygen according to the balanced equation.
From balanced equation, 1 mole of oxygen reacts with 2 moles of hydrogen.
So, let's convert grams of oxygen to moles and multiply it by the mole ratio to calculate the moles of hydrogen that are easily converted to grams on multiplying by it's molar mass.
The complete set up looks as:

= 
Hence, the right option is B:
.
Answer is (4) - Se.
Among the given choices Se has the highest electronegativity value as 2.4 compared to others. Hence, Se shows <span>greatest attraction for electrons in a chemical bond.
</span>Electronegativity is
a value that tells us how an atom can attract electrons towards itself. <span>If
the electronegativity is high, then the attraction to the electrons is also high.
</span>
Answer:
1.004×10²²
Explanation:
The molar mass of carbon is 12 g/mol
which means that:
<u>1 mole of carbon atoms has a mass of 12 grams.</u>
Since, diamond is a allotrope of carbon.
Mass of 1.00-carat diamond in grams is:
1.00 carat = 0.200 g
<u>
Since, 1 mole of C contains 6.022×10²³ atoms of C</u>
So,
12 grams contains 6.022×10²³ atoms of C
1 gram contains 6.022×10²³/ 12 atoms of C
0.200 gram contains (6.022×10²³/ 12)×0.200 atoms of C
Thus,
<u>1 carat diamond contains 1.004×10²² atoms of C.</u>