Introduction to Noble Gases

Q.

Why do the electron configurations of chromium and copper seem to disagree with what is expected according to the Aufbau principle?

Q.

Helium is the second most abundant element in the Universe. Yet, it is not the most abundant on Earth - Why?

1. Both a and b are correct.

2. Helium atoms are small and cannot be retained by the Earth's gravitational field.

3. Helium is highly reactive and constantly undergoes chemical transformation.

4. Helium is peculiarly attracted only to black holes.

Q.

What is the difference between fractional abundance and natural abundance?

Q.

Why does Scandium have a 3 plus charge?

Q.

The shells around the nucleus are called energy levels. Why?

Q.

Which one of the following has maximum number of atoms?

1. $\text{1 g of Mg(s)}$[Atomic mass of $\text{Mg = 24}$]
2. ${\text{1 g of O}}_2\text{(g)}$[Atomic mass of $\text{O = 16}$]
3. $\text{1 g of Li(s)}$[Atomic mass of $\text{Li = 7}$]
4. $\text{1 g of Ag(s)}$[Atomic mass of $\text{Ag = 108}$]

Q.

Name the third most abundant element in the universe?

Q.

Which of the following outer electronic configuration represent argon?

1. ${\mathrm{ns}}^2$

2. ${\mathrm{ns}}^2{\mathrm{np}}^6$

3. ${\mathrm{ns}}^2{\mathrm{np}}^5$

4. ${\mathrm{ns}}^2{\mathrm{np}}^4$

Q.

What are noble gases . Name all in the increasing order of their densities

Q.

An element have two isotopes with mass number 16 and 18.The average atomic weight is 16.5.The percentage abundance of these isotopes are _______and____________respectively.

1. 75, 25

2. 25, 75

3. 50, 50

4. 33.33, 66.67

Q. In case of group III elements, the inert pair effect is predominant in

1. Boron
2. Aluminum
3. Indium
4. Thallium

Q. Among Group 18 elements, is the most abundant element on the Earth’s crust and is the last element of group.

1. Argon
2. Neon
3. Helium
4. Oganesson

Q.

What is differentiating electron? Give an example

Q. (1) Calculate the amount of carbon dioxide that could be produced when
$A)$ $1mole$ of carbon is burnt in air.

(2) Calculate the amount of carbon dioxide that could be produced when
$B)$ $1mole$ of carbon is burnt in $16g$ of dioxygen.

(3) Calculate the amount of carbon dioxide that could be produced when
$C)$ $2mole$ of carbon are burnt in $16g$ of dioxygen.

Q. The limiting composition of f - block hydraides????

Q. Use the data given in the following table to calculate the molar mass of naturally occuring argon isotopes:

$\begin{array}{ccc}\text{Isotopes}& \text{Isotopic molar mass}& \text{Abundance}\\ {}^{36}\text{Ar}& 35.96755gmo{l}^{-1}& 0.337\%\\ {}^{38}\text{Ar}& 37.96272gmo{l}^{-1}& 0.063\%\\ {}^{40}\text{Ar}& 39.9624gmo{l}^{-1}& 99.600\%\end{array}$

Q. Why the elements of group $18$ are also known as noble gases?

Q. Which of the following is a noble gas?

1. $He$
2. $N_2$
3. $H_2$
4. $O_2$

Q. Noble gases are strongly soluble in water, owing to:

1. dipole - dipole interactions
2. dipole - induced dipole interactions
3. hydrogen bonding
4. induced dipole - instantaneous dipole interactions

Q. Which among the following is inert gas and not very soluble in water too?

1. $O_2$
2. ${CO}_2$
3. $N_2$
4. $He$
5. $H_2{SO}_4$

Q.

In the present periodic table containing 118 elements: How many zero group elements exist?

Q. The electronic configuration of few elements is given below. Mark the statement which is not correct about these elements.
(i) $1s^{2}2s^{2}2p^{6}3s^1$
(ii) $1s^{2}2s^{2}2p^5$
(iii) $1s^{2}2s^{2}2p^6$
(iv) $1s^{2}2s^{2}2p^3$

1. (i) and (ii) form ionic compounds.
2. (iii) is a noble metal.
3. (i) is an alkali metal.
4. (iv) has high ionisation enthalpy.

Q. What are noble gases? Name all in the order of their increasing density.

Q.

Name the element which has the highest ionization energy?

Q.

Explain:
Inert gases.

Q.

What are metalloids? Give examples of any two metalloids in the periodic table and write their electronic configuration.

Q. The noble gas that does NOT occur in the atmosphere is:

1. $He$
2. $Ne$
3. $Kr$
4. $Ra$

Q. The number of valence electrons present in noble gases is:

1. $6$
2. $18$
3. $8$
4. $4$

Q. Zero group elements are known as____________.

1. alkali metals
2. alkaline earth metals
3. transition metals
4. inert gases

Q.

Of the group 18 elements, __ is the most abundant in the Earth’s crust.