Advertisements
Advertisements
प्रश्न
The mass of one atom of an element X is 2.0 × 10–23 g.
Calculate the atomic mass of element X.
What could element X be ?
Advertisements
उत्तर
Given:
Mass of an atom of element X = 2.0 × 10-23g
We know that the mass of an atom of a substance is equal to the mass of 1 mole of that substance. 1 mole of a substance consists of 6.022 × 1023 atoms; therefore, the mass of an atom of a substance is equal to the mass of 6.022 × 1023 atoms.
Therefore, to calculate the atomic mass of element X, we need to calculate the mass of 6.022 × 1023 atoms of X.
Mass of 1 atom of X = 2.0 × 10-23
Mass of 6.022 × 1023 atoms of X = 6.022 × 1023 × 2.0 × 10-23 = 12 u
Hence, the atomic mass of element X is 12 u.
Carbon has an atomic mass of 12 u; therefore, element X is carbon.
APPEARS IN
संबंधित प्रश्न
What is the numerical value of Avogadro number ?
What name is given to the number 6.022 × 1023 ?
What name is given to this number ?
What is the number of molecules in 1.5 moles of ammonia ?
If 32 g of sulphur has x atoms, then the number of atoms in 32 g of oxygen will be :
If 12 gram of carbon has x atoms, then the number of atoms in 12 grams of magnesium will be :
What weight of oxygen gas will contain the same number of molecules as 56 g of nitrogen gas ?
(O = 16 u ; N = 14 u)
What mass of nitrogen, N2, will contain the same number of molecules as 1.8 g of water, H2O ?
(Atomic masses : N = 14 u ; H = 1 u ; O = 16 u)
How many grams of magnesium will have the same number of atoms as 6 grams of carbon ?
(Mg = 24 u ; C = 12 u )
Classify each of the following on the basis of their atomicity.
- F2
- NO2
- N2O
- C2H6
- P4
- H2O2
- P4O10
- O3
- HCl
- CH4
- He
- Ag
Which has more number of atoms?
100g of N2 or 100 g of NH3
A gold sample contains 90% of gold and the rest copper. How many atoms of gold are present in one gram of this sample of gold?
Compute the difference in masses of one mole each of aluminium atoms and one mole of its ions. (Mass of an electron is 9.1×10–28 g). Which one is heavier?
A silver ornament of mass ‘m’ gram is polished with gold equivalent to 1% of the mass of silver. Compute the ratio of the number of atoms of gold and silver in the ornament.
The atomic number of calcium and argon are 20 and 18 respectively, but the mass number of both these elements is 40. What is the name given to such a pair of elements?
Helium atom has 2 electrons in its valence shell but its valency is not 2, Explain
An element X has a mass number 4 and atomic number 2. Write the valency of this element?
