Advertisements
Advertisements
प्रश्न
Elements X, Y, Z have atomic numbers 6, 9 and 12 respectively. Which one:
- forms anion – negative ion;
- forms cation – positive ion;
- has 4 electrons in the outermost orbit. [Y, Z, X]
उत्तर
Atomic number of
X = 6 = number of electrons (2, 4)
∴ X has 4 electrons in outermost orbit.
Y = 9 = number of electrons (2, 7)
∴ Y form anion = negative ion
Z = 12 = [2, 8, 2]
∴ Z forms cation – positive ion.
APPEARS IN
संबंधित प्रश्न
Name the particles which actually determine the mass of an atom.
(a) What is meant by (i) atomic number, and (ii) mass number, of an element? Explain with the help of an example.
(b) What is the relation between the atomic number and mass number of an element?
(c) If an element M has mass number 24 and atomic number 12, how many neutrons does its atom contain?
From the symbol `""_15^31"P"`, state : atomic number of phosphorus
Define the following form:
Atomic number
Define the term ‘mass number’ of an atom.
Match the statements in List I with the correct answer from List II.
| List I | List II |
| 1. Mass number of an atom is the number of protons and | A: Electron |
| 2. The sub-atomic particle with a negligible mass. | B: Argon |
| 3. An atom having stable electronic configuration. | C: Nitrogen |
| 4. A molecule formed by sharing of electrons [covalency] | D: Sodium |
| 5. A metallic atom having unstable electronic configuration. | E: Neutrons |
An element ‘A’ has mass number 23 and atomic number 11. State the –
- no. of neutrons in its shell,
- electronic configuration of the element ‘A’.
Match the following:
| Column A | Column B | ||
| 1. | K shell | a. | 8 |
| 2. | L shell | b. | 32 |
| 3. | M shell | c. | 2 |
| 4. | N shell | d. | 18 |
If M is the atomic mass and A is the mass number, then packing fraction is given by ______.
A group of elements in the periodic table is given below (Boron is the first member of the group and Thallium is the last).
Boron, Aluminium, Gallium, Indium, Thallium
Answer the following question in relation to the above group of elements:
The atomic number of boron is 5. Write the chemical formula of the compound formed when boron reacts with chlorine.
