Answer :
According to the law of conservation of mass, the mass of reactants must be equal to the mass of products.
The balanced chemical reaction is,
As we know that the molar mass of magnesium is 24 g/mole, the molar mass of 
is 32 g/mole and the molar mass of magnesium oxide is 40 g/mole.
From the given balanced reaction, we conclude that
As, 1 mole of magnesium react 
mole of oxygen to give 1 mole of magnesium oxide.
So, the mass of Mg is 24 g, the mass of 
and the mass of MgO is 40 g.
That means 24 g of Mg react with 16 g to give 40 g of MgO.
Answer: A pattern of same atomic orbitals can be seen about elements in the same period with respect to electron structures.
Explanation:
The horizontal rows in a period table are called periods.
Elements present in the same period will have same atomic orbitals.
For example, electronic distribution of Na is 2, 8, 1 and it is a third period element.
Similarly, electronic distribution of Cl is 2, 8, 7 and it is also a third period element.
Hence, both Na and Cl will have K, L, M shells, that is, they have three atomic orbitals.
Thus, we can conclude that a pattern of same atomic orbitals can be seen about elements in the same period with respect to electron structures.
... and a power ot ten.
For example: 1,3x10^21 is in scientific notation, but 13x10^20 is not in scientific notation.
