Oxidation States

Q.

Shortcut to learn periodic table

Q.

What is the electronic configuration of Bromine?

Q. Why does phosphorus show two valencies (3 and 5) ? Wouldn't it be easier to gain 3 electrons rather than losing 5 electrons? I mean if phosphorus loses five electrons, it'll have a 5+ charge, which is quite unstable, as explained in this video for carbon: https://youtu.be/4E8ShsaWssA .

Q.

Anything that influences the valence electrons will affect the chemistry of the element. Which one of the following factors does not affect the valence shell?

1. Number of core electrons.

2. Nuclear charge (Z).

3. Nuclear mass.

4. Valence principle quantum number (n).

Q.

The number of electrons in an atom of Fluorine is 9. Its electronic configuration is _______ .

1. 1, 8

2. 2, 7

3. 8, 1

4. 7, 2

Q.

What is the maximum covalency of first elements of each group?

Q.

An element belongs to Group 17 and the third period of the periodic table. Write the following:

Its metallic and non-metallic nature.

Q.

Define valency and valence shell.

Q.

Hydrogen resembles halogens in many respects for which several factor are responsible.Of the following factors which one is the most important in this respect?

1. Its tendency to lose an electron to form a cation

2. Its tendency to gain a single electron in its valency shell to attain stable electronic configuration

3. Its small size

4. Its low negative electron gain enthalpy

Q. Question 38
Write the formula of the product formed when the element A (atomic number 19) combines with the element B (atomic number 17). Draw its electronic dot structure. What is the nature of the bond formed?

Q.

In any period, the valency of an element

1. Increases one by one from IA to IVA and then decreases from VA to VIIA one by one

2. Decreases one by one from IA to IVA and then increases from VA to VIIA one by one

3. Increases one by one from IA to VIIA

4. Decreases one by one form IA to VIIA

Q.

An atom with 10 protons is stable because it's __________ is complete.

1. Duplet

2. Valence charge

3. Octet

4. Nucleus

Q.

An atom of an element has an electronic configuration 2, 8, 6.

Name the element that shows chemical similarity.

Q.

Periodic table with names

Q.

The valency of atoms can be zero when:

1. All of these.

2. Outer most orbit achieves octet

3. Outer most orbit gets completely filled

4. Outer most orbit has same number of electrons as the valence electrons of noble gases.

Q. Question 44 (e)
Atomic number of a few elements are given below 10, 20, 7, 14. Determine the valency of these elements.

Q.

Which among the given elements have similar chemical properties, as an atom of an element 'X' with an electronic configuration of 2, 8, 5?

1. F (9)

2. Na (11)

3. N (7)

4. Ar (18)

Q.

Statement 1 (S1): Phosphide ion is an example of ​a polyatomic ion.​
Statement 2 (S2): Phosphide ion combines with 2 cations, ​hence it has a valency of 2.​

Q. Elements with stable electronic configurations can have maximum of ___ electrons in their outermost shell.

Q. Question 1
How will you find the valency of chlorine, sulphur and magnesium?

Q.

Element X can donate 4 electrons, X would most likely belong to the same group in the periodic table as that of

1. Na

2. Mg

3. Al

4. Si

Q. Give the electronic configuration of Cl^- ion?

Q. Without consulting the periodic table, select from each of the following sets, the elements belonging to the same group of the periodic table

1. Z=11, 3, 20, 37

2. Z=12, 38, 4, 88

3. Z=31, 13, 81, 50

4. Z=21, 39, 90, 57

Q. lithium , sodium and potassium are placed in one group on the basis of their similar properties of these element

Q. Question 5 (b)
An atom has electronic configuration 2, 8, 7.
To which of the following elements would it be chemically similar? (Atomic numbers are given in parentheses).

N (7), F (9), P (15), Ar(18).

Q.

An atom has electronic configuration 2, 8, 7.
What is the atomic number of this element?

1. 14

2. 17

3. 16

4. 15

Q.

explain the term variable valency.