What element is represented by 1s22s22p63s23p64s5

                  Calcium

                          The position of an element in representative blocks of periodic table can be located by finding out its valence shell and the number of valence electrons present in that particular valence shell.

The electronic configuration given is as follow,

                                    1s², 2s², 2p⁶, 3s², 3p⁶, 4s²

Remember than the s orbital can accomodate the maximum of 2 electrons hence, the 5 can be ignored.

As the valence shell is 4 it means that the element is present in period 4 and the number of electrons in shell 4 are two hence, the group number is 2.

On inspecting group 2 and period 4 we found that the element is Calcium.

out of these options:

ability to burn paper

pure sodium reacting violently with water

the boiling point of water

helium does not tend to react with anything

i would say this is a physical property:

helium does not tend to react with anything

why? :

i said helium does not tend to react with anything because well, it reacts to ! but ability to burn paper, pure sodium reacting violently with water, & the boiling point of water are chemical or

physical properties: the properties of a substance that can be observed without changing the chemical makeup of the substance

chemical properties: properties of a substance relating to the chemical nature and reactivity of the substance

it is a solid

explanation: