Atomic Number

Q.

What is an isotope and Give any three applications of isotopes

Q.

Boron has two isotopes ${\mathrm{B}}^{10}$ and ${\mathrm{B}}^{11}$ whose relative abundances are $20\%$ & $80\%$respectively. The average atomic weight of Boron is

Q. How to find electronic configuration of an element ?

Q.

Calculate the binding energy and binding energy per nucleon (in MeV) of a Nitrogen nucleus ${}^{7}N_{14}$ from the following data: Mass of proton = 1.00783 u, Mass of neutron = 1.00867 u, Mass of Nitrogen nucleus = 14.00307 u.

Q.

What is the ground-state electron configuration for ${\mathrm{O}}^{2-}$ ion?

Q.

What is the difference between ions and radicals?

Q.

What is the electron configuration of mercury?

Q.

The atom of an element X has 7 electrons in its M shell.
(a) Write the electronic configuration of element X.
(b) What is the atomic number of element X?
(c) Is it a metal or a non-metal?
(d) What type of ion will be formed by an atom of element X? Write the symbol of the ion formed.
(e) What could element X be?

Q.

State the difference between a shell and a subshell?

Q.

What is the ground-state electron configuration of a neutral atom of iodine?

Q.

An atom of an element has two electrons in the M shell. What is the (a) atomic number (b) number of protons in this element ?

Q.

What is the mass number of potassium?

Q.

The electronic configuration of Neon is?

Q.

The electronic configuration of an element Z is 2, 8, 8.
(a) What is the atomic number of the element?
(b) State whether element Z is a metal or non-metal.
(c) What type of ion (if any) will be formed by an atom of element Z? Why?
(d) What is special about the outermost electron shell of the atom of this element?
(e) Give the name and symbol of element Z.
(f) Name the group of elements to which Z belongs.

Q.

Calculate the atomic mass of Aluminium.

Q.

What is the charge on an electron?

Q.

Question 19
Complete the following table.

Q.

What is the usual symbol for neutron?

Q.

The atom of an element X has 18 protons, 22 neutrons and 18 electrons. The atomic number of the element is ___

Q.

What is mass number of an element? How is the mass number related to the protons and neutrons present in the nucleus of an atom?

Q.

The nucleus of an atom has 5 protons and 6 neutrons. What would be the (a) atomic number, (b) mass number, (c) the number of electrons, and (d) the number of valence electrons, per atom of this element?

Q.

What are nucleon? What are their number called?

Q. Question 3 (b)
Name two elements that have two electrons in their outermost shell

Q. Question 8
Explain with examples
(i) Atomic number,
(ii) Mass number,
(iii) Isotopes and
(iv) Isobars.
Give any two uses of isotopes.

Q.

Chlorine is an element of atomic number 17. It is a mixture of two isotopes having a mass number of 35 and 37.

Write down the electronic configuration of the chlorine atom.

Q.

The atomic number of an element X is 13. What will be the number of electrons in its ion $X^{3+}$?

1. 11

2. 15

3. 16

4. 10

Q.

In the following table the mass number and the atomic number of certain elements are given

Making use of these data find. 1. Cation 2. Anion 3.a pair of isotopes 4. an atom of noble gas

Q.

How do you calculate the atomic number of an element?

Q.

The atomic number of an element E is 16. The number of electrons in its ion $E^{2-}$ will be:

1. 15

2. 18

3. 16

4. 14

Q.

From the symbol ${}_{15}^{31}\text{P}$, state:
(i) mass number of phosphorus,
(ii) atomic number of phosphorus, and
(iii) electron configuration of phosphorus.