Answer:
Dmitri Mendeleev
used patterns to predict undiscovered
elements
Johann Wolfgang Dobereiner
created groups of three elements,
each based on similar properties
John Newlands
arranged elements according to their
atomic mass
Antoine Lavoisier,
divided elements into four categories
✓
Answer:
nitrogen according to periodic table
Uranium provides nuclear fuel used generate electricity in nuclear power station,also used by the military to power nuclear submarines and in nuclear weapons.
Answer:
the molecular formula of the compound is N2O4
Explanation:
- Find the empirical formula
mole of N present = mass of N divided by molar mass of N = 0.140/14 = 0.01 mole
mole of O present = mass of O divided by molar mass of O = 0.320/16 = 0.02 mole
Divide both by the smallest number of mole to determine the coefficient of each, the smallest number of mole is 0.01 thus:
quantity of N = 0.01/0.01 = 1
quantity of O = 0.02/0.01= 2
thus the empirical formula = NO2
- Now determine the molecular formula by finding the ratio of molecular formula and empirical formula
Molar mass of molecular formula = 92.02 amu = 92.02 g/mole
Molar mass of empirical formula NO2 = (14 + (16 x 2)) = 46 g/mole
the x factor = 92.02/46 = 2
Molecular formula = 2 x NO2 = N2O4