Advertisements
Advertisements
Question
Right or wrong sentence.
The K and L shells of the elements Na and Mg contain electrons.
Options
Right
Wrong
Advertisements
Solution
The given sentence is right.
Explanation:
- Both sodium (Na) and magnesium (Mg) have electrons in their K and L shells; specifically, their K shells are filled with 2 electrons and their L shells are filled with 8 electrons.
- While they also have electrons in their M shells (1 and 2, respectively), it is factually accurate to state that the K and L shells contain electrons.
APPEARS IN
RELATED QUESTIONS
How many rows and columns are there in the modern periodic table?
How does the metallic character of elements in Modern Periodic Table vary on moving from left to right in a period, and (ii) down a group?Give reason to justify your answer.
Give two example of group 1 elements.
The atomic numbers of four elements P, Q, R and S are 6, 8, 14 and 16 respectively. Out of these, the element known as metalloid is:
(a) P
(b) Q
(c) R
(d) S
Consider the following elements:
Na, Ca, Al, K, Mg, Li
Which of these elements belong to the same group of the periodic table?
Which element has two shells, both of which are completely filled with electrons?
Which element has the electronic configuration 2, 8, 2?
How would the tendency to gain electrons change on moving from left to right in a period of the periodic table?
State how the valency of elements varies in a group of the periodic table?
What is the main characteristic of the last elements in the periods of the periodic table? What is the general name of such elements?
In what respects do the properties of group 1 elements differ from those of group 17 elements? Explain with examples by taking one element from each group.
Consider the following elements:
20Ca, 8O, 18Ar, 16S, 4Be, 2He
Which of the above elements would you expect to be:
(i) very stable?
(ii) in group 2 of the periodic table?
(iii) in group 16 of the periodic table?
The elements A, B, C and D belong to groups 1, 2, 14 and 17 respectively of the periodic table. Which of the following pairs of elements would produce a covalent bond?
(i) A and D
(ii) C and D
(iii) A and B
(iv) B and C
(v) A and C
An element X belongs to 3rd period and group 2 of the periodic table. State:
(a) number of valence electrons
(b) valency
(c) metal or non-metal
(d) name of the element
Correct the statement.
Copper and zinc are representative elements.
Name two elements in halogens.
Name the type of elements which have two electrons in the outermost orbit.
State the modern periodic law.
What is meant in the periodic table by a period?
Name and state the following with reference to the elements of the first three periods of the periodic table.
A covalent compound formed by an element in period 2 and a halogen.
In the Modern Periodic Table – atoms of all elements are arranged according to their increasing order of – atomic numbers. An atom of nitrogen has seven protons and seven electrons. State what would be its atomic number.
Give the symbol and valency of the following element and radical.
Oxygen [Oxide]
Give the symbol and valency of the following element and radical.
Sulphate
Give the chemical formula of carbonic acid
Give the chemical formula of calcium phosphate
Fill in the blank:
The element lithium in the Modern Periodic Table with valency 1+ belongs to the group ______.
What are the periods in a periodic table?
Which of the following statements about the Modern periodic table is correct?
Find the odd one out and give its explanation.
Write an explanation.
Period
In the modern periodic table, the positions of 1 to 20 elements are shown here. Identify the elements A and B. Write their atomic number.

On moving from left to right in a period in the periodic table, the size of the atom ______
An element which is an essential constituent of all organic compounds belongs to
The element with atomic number 14 is hard and forms acidic oxide and a covalent halide. To which of the following categories does the element belong?
“Hydrogen occupies a unique position in Modern Periodic Table”. Justify the statement.
Choose an element from period 3 of modern periodic table that matches the description given below in instance. Give a reason for your choice.
It has same valency as Lithium.
Name two elements that you would expect to show chemical reactions similar to calcium. What is the basis of your choice?
Name the metalloids in the first twenty elements.
