Groups in Modern Periodic Table

Q.

At present how many elements are known?

Q.

Differentiate between a group and period of the periodic table.

Q.

Valency of Noble gases is zero.

1. True

2. False

Q.

Name three divalent cations with their formulae and valencies.

Q. How many electrons are there in the outermost shell of an oxygen atom?

1. 1

2. 6
3. 8
4. 2

Q.

Which of the following has the most non-metallic character?

1. N
2. C
3. F
4. O

Q. From the formula of CO2, we can frame the valencies of carbon and oxygen. But, the valencies of Carbon and oxygen will differ when in Carbon - Monoxide(CO). What is the reason ?

Q. In the modern periodic table, there are ___

1. 18 groups
2. 18 periods
3. 7 periods
4. 7 groups

Q.

How does metallic character change in a group?

Q.

Define electropositivity. Which is the most electropositive element in the periodic table?

Q.

How does the metallic character vary in a group of the periodic table?

Q.

The modern periodic table is divided into how many blocks?

Q. Element X forms a chloride with the formula $XC{l}_2$, which is a solid with a high melting point. X would most likely be in the same group of the periodic table as______.

1. Sodium
2. Magnesium
3. Silicon
4. Aluminium

Q.

Question 39
Arrange the following elements in the increasing order of their metallic character Mg, Ca, K, Ge, Ga

Q.

Name the element that has not yet been reacted with ${\mathrm{F}}_2$?

Q. Which of the following elements are alkali metals?

1. Aluminium
2. Calcium
3. Potassium
4. Sodium

Q.

when fomation of NaCl electron configuration Na loss one atom and Cl gain this atom in this situation Na and Cl are both atom are stable or not.

Q.

Which of the following elements has completely filled outermost shells?

1. Neon (Ne)

2. Argon (Ar)

3. Xenon (Xe)

4. Lithium

Q. An element X has an atomic number of 15. Which of the following elements will show chemical properties similar to X?

1. Be (4)
2. Ne (10)
3. O (8)
4. N (7)

Q.

The second and third periods have ____________elements are called ___________ periods.

Q. How to write a chemical formula for hydrogen sulphide and Aluminium hydroxide.
And what are their valencies?

Q.

Which elements are called inner transition elements in the modern periodic table?

Q.

Which is the least reactive element in group 17?

1. Iodine
2. Bromine
3. Fluorine
4. Chlorine

Q. The common property amongst Be, Mg, Ca, Sr, Ba and Ra in the modern periodic table is-

1. Equal number of electrons.
2. Equal number of electrons in the valence shell.
3. Same number of shells.
4. All of the above.

Q.

What do you mean by representative elements? Give example.

Q.

Silicon and phosphorous belongs to same period of the periodic table.

1. State the electronic configuration of silicon and phosphorous.
2. Name the period in which above element occur.

Q.

what is halogens?

Q.

Give the name and symbol of following elements which occupy each of the following positions in the periodic table:

Period 3, group VII A

Q.

All the elements in the same group of the modern periodic table have the same number of valence electrons.

1. True

2. False

Q.

Where is Carbon found?