Ions

Q.

Why do some elements have variable valency

Q.

Whenever lithium loses its one electron , it is said to be stable. But there after losing one electron , there would be 3 protons and 2 electrons so it has a positive charge right ? So how come it is stable after losing one electron ?

Q.

In chlorine, when the protons and electrons are equal, the charges cancel each other and the atom remains neutral. Then how does it accept one more electron when there is no force to act on it?

Q.

A metal with low melting and boiling points is ________

1. F

2. K

3. B

4. I

Q.

A negatively charged ion called --------------------- is formed by gaining one or more electrons by an atom.

Q. In the atom of an element, seven electrons are present in the outermost shell. If it acquires an inert gas configuration by receiving more electrons, charge on the ion formed will be:​

1. 7-
2. 1+
3. 7+
4. 1-

Q.

The atom of an element A has three electrons in the outermost shell.

It loses one of these to the atom of another element B.

What will be the nature and value of charge on the ion which results from A ?

Q.

Hydrogen chloride is a ___ made of H⁺ and Cl^- which are ___ and ___ respectively.

1. Compound, Cation and Anion.

2. Ion, Cation and Anion.

3. Element, Molecule and Molecule.

4. Compound, Anion And Cation.

Q. Which of the following hold true for Zinc ion?

1. Anion, positive
2. Cation, Positive
3. Anion, negative
4. Cation, negative

Q. A neutral atom of an element has a nucleus with a nuclear charge 11 times and mass 23 times as that of a hydrogen nucleus. What is the ratio of electrons to protons in its stable positively charged ion?​

1. 23 : 11
2. 10 : 11
3. 20 : 21
4. 10 : 12

Q. Name the ions present in Calcium Phosphate ________

Q. Li has 1 electron in its outer shell, Cl has 7 electrons in its outer shell. Choose the correct option:

1. Li and Cl have valency +1 and -6 respectively
2. Li and Cl have valency +1 and -7 respectively
3. Li and Cl have valency +1 and -1 respectively
4. Li and Cl have valency 0 and -1 respectively

Q. When a neutral atom loses an electron, it is called _____ and when it gains an electron, it is called _____.

Q. Which among the following non-metals is in its liquid form?

1. Hydrogen
2. Carbon
3. Bromine
4. Phosphorus

Q. An _________ ion which combines with a polar covalent molecule (______) to form an ammonium ion.

Q. Match the following indicators to the respective colour change in the acidic or basic medium:

1. Green (basic)
2. Red (acidic)
3. Yellow (basic)
4. Colourless (acidic)

Q. What are polyatomic ions? Give examples.