The answer would be 5. because the last zero is a holding place because the number is in front of the decimal. They other zero counts because they are being sandwiched.<span />
The term Big Bang defines that the Universe has expanded from the ancient hot and thick primary situation at some fixed time in the past.
Big Bang theory refers to the origin of the Universe. In the beginning, universe is very heavy and small hot ball of matter. It was a point no bigger than the head of a pin when all the things squished with each other and universe is expanded with huge explosion of energy. Due to expansion, it is cooled and results in the formation of Stars and galaxies. After sometime, atoms formed like helium and hydrogen.
Thus, statement (1), (3) and (4) is correct whereas statement (2) and (5) is incorrect.
The number of atoms of phosphorus in copper (II) phosphate [Cu3 (PO4)2] is determined by multiplying first 9.20 by 2 since there are two phosphorus atoms in the compound and multiplying again with Avogadro's number. The answer is 1.108 x 10^25 atoms.
Answer:
A chemical reaction expresses a chemical change. For example, one chemical property of hydrogen is that it will react with oxygen to make water. We can write that as follows:
hydrogen reacts with oxygen to make water
We can represent this chemical change more succinctly as
hydrogen + oxygen → water
where the + sign means that the two substances interact chemically with each other and the → symbol implies that a chemical reaction takes place. But substances can also be represented by chemical formulas. Remembering that hydrogen and oxygen both exist as diatomic molecules, we can rewrite our chemical change as
H2 + O2 → H2O
Answer:
1.536×10^23
Explanation:
One mole of any compound has N molecules.
Where N is the Avogadro's number
Molecular weight of H2SO4 is
H2 = 2
SO4 = 96
H2SO4 = 2+96
98g/mol
Hence the number of mole of H2SO4 in 25g = 25/98 = 0.2551mol
Number of molecules = 25/98 × 6.022×10^23
= 1.536×10^23 molecules
