Atomic Number

Q.

Arrange the following elements in the order of their increasing nonmetallic character $\mathrm{Li},\mathrm{O},\mathrm{C},\mathrm{Be},\mathrm{F}$.

1. $\mathrm{F}<\mathrm{O}<\mathrm{C}<\mathrm{Be}<\mathrm{Li}$

2. $\mathrm{Li}<\mathrm{Be}<\mathrm{C}<\mathrm{O}<\mathrm{F}$

3. $\mathrm{F}<\mathrm{O}<\mathrm{Li}<\mathrm{Be}<\mathrm{C}$

4. $\mathrm{F}<\mathrm{O}<\mathrm{Be}<\mathrm{C}<\mathrm{Li}$

Q.

(b) Two elements X and Y have atomic numbers 12 and 16 respectively. Write the electronic configuration for these elements. To which period of the modern periodic table do these two elements belong? What type of bond be formed between them and why?

Q. Identify the correct option that contains group - I elements arranged in the increasing order of their atomic number.

1. Li, Na, K, Rb, Fr
2. Be, Mg, Ca, Sr, Ra
3. Fr, Rb, K, Na, Li
4. F, Cl, Br, I, At

Q. The outermost subshell-wise electronic configuration of an element Y (Symbol is not real) is $3s^{2}3p^4$. To which period and group does this element belongs?

Q.

The total number of protons present in the nucleus of an atom is referred to as the ____________(atomic number/ mass number).

Q.

Define: Relative atomic mass.

Q.

The arrangement of elements in the increasing order of their atomic number in the tabular format is known as _________.

Q. Elements 'X' and 'Y' have their electronic configuration as $x,x^3,x^3–1$ and $x,x^3,x^2–3$. Which of the following is correct for elements 'X' and 'Y'?

1. Both the elements are metallic
2. Both the elements are inert
3. Both the elements belong to same group
4. Both the elements belong to same period

Q.

Elements X, Y, Z have atomic numbers 6, 9 and 12 respectively. Which one:

(i) forms anions - negative ions;

(ii) form cations - positive ions;

iii) has 4 electrons in the outermost orbit ?

Q.

The element X in group 17 has 3 shells, if so,

a) Write the subshells electronic configuration of the element.
b) Write the period number.

Q. The atomic number of magnesium is 12. How many protons are there in the nucleus of magnesium atom? How many electrons and protons does an ion of magnesium which has a charge of +2 contain.

1. 10, 10
2. 10, 13
3. 11, 12
4. 10, 12

Q. Elements X, Y, and Z have atomic numbers 6, 9, and 12 respectively. Which one has four electrons in its valence shell?

1. X
2. Y
3. Z
4. Both A and B

Q. Subshell electronic configuration of two elements are given. To which block, period and group does each belong

$\left(a\right)1s^{2}2s^{2}2p^{6}3s^2\left(b\right)1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}3d^{3}4s^2$

Q. The total number of in an atom determines its atomic number.

1. neutrons
2. protons
3. electrons

Q. Magnesium chloride is an ionic compound formed by magnesium and chloride ions. The overall charge on its molecule will be _____.

1. +1
2. 0
3. + 2
4. -1

Q. Summarize the rules for writing of distribution of electrons in various shells for the first eighteen elements.

Q. Identify the correct option that contains group - I elements arranged in the increasing order of their atomic number.

Q. The total number of electrons in one molecules of carbon dioxide is :

1. 22
2. 44
3. 66
4. 88