Advertisements
Advertisements
प्रश्न
An element X has a mass number 4 and atomic number 2. Write the valency of this element?
Advertisements
उत्तर
The element X has its atomic number as 2. Thus, an atom of X contains two electrons in it. These 2 electrons fill the X-shell completely.
Thus the valency of X is zero.
APPEARS IN
संबंधित प्रश्न
An element has an atomic number of 11 and its mass number is 23. What is the arrangement of electrons in the shells? State nuclear composition of an atom of the element.
The atomic number of an element E is 16. The number of electrons in its ion E2– will be :
What name is given to the number 6.022 × 1023 ?
What name is given to this number ?
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 :
Which of the following has the maximum number of atoms ?
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)
If one gram of sulphur contains x atoms, calculate the number of atoms in one gram of oxygen element.
(Atomic masses : S = 32 u ; O = 16 u)
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 ?
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?
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.
. A sample of ethane (C2H6) gas has the same mass as 1.5 ×1020 molecules of methane (CH4). How many C2H6 molecules does the sample of gas contain?
In the atom of an element X, 6 electrons are present in the outermost shell. If it acquires noble gas configuration by accepting requisite number of electrons, then what would be the charge on the ion so formed?
Match the names of the Scientists given in column A with their contributions towards the understanding of the atomic structure as given in column B
| (A) | (B) | ||
| (a) | Ernest Rutherford | (i) | Indivisibility of atoms |
| (b) | J.J.Thomson | (ii) | Stationary orbits |
| (c) | Dalton | (iii) | Concept of nucleus |
| (d) | Neils Bohr | (iv) | Discovery of electrons |
| (e) | James Chadwick | (v) | Atomic number |
| (f) | E. Goldstein | (vi) | Neutron |
| (g) | Mosley | (vii) | Canal rays |
Helium atom has 2 electrons in its valence shell but its valency is not 2, Explain
