There are 18groups in modern periodic table.
- The modern periodic table is discovered by famous scientist Henry Mosley in 1914.
- The modern periodic table is also called long term periodic table.
- It has 7periods and 18groups.
The average atomic mass of the element = 35.5
calculation
average atomic mass = sum of the masses of its isotope each multiplied by its natural abundance.
that is
[(75 x35) +(25 x37)] /100 = 35.5
Its ester look in table R of your reference table
Answer:-
4.765 grams
Explanation:-
Molecular weight of Hydrogen gas H2 = 1 x 2 = 2 gram
Molecular weight of NH3 = 14 x 1 + 1 x 3 = 17 gram
The balanced chemical equation for the reaction is
N2 + 3 H2 --> 2 NH3
From the chemical equation we see
To produce 2 NH3 we need 3 H2 to react.
∴ To produce 2 x 17 grams of NH3 we need 3 x 2 grams of H2 to react.
To produce 27 grams of NH3 we need (3 x 2) x 27 / (2 x 17) grams of H2 to react
=4.765 grams of H2 to react