Question

an element has atomic number 3. To which period of the periodic table does it belong ? Give reason for your answer​

Answer 1

Answer: The element is lithium

Explanation: lithium belongs to group 2 because its electronic configuration is 1s2. 2s1

Answer 2

Answer:

Period number = 2

Explanation:

Let's first find the electronic configuration of the element.

Atomic number of the element = 3

Electronic configuration = 2 , 1

Since, the number of shells of the element is equal to the period it belongs to in the periodic table.

Since, this element has two 2 orbits so it belongs to period 2 in the periodic table.

Though it is not required to mention the name of element in such questions, I am mentioning it for general information.

Element is Lithium(denoted by Li)