Why does the first period of the periodic table contain only two elements while all other periods have eight or more periods have eight or more elements in them?

Answer 1

Because it corresponds to the filling of the 3s and 3p subshells (of the third shell) which take a total of 8 electrons, two in the 3s and 6 in the 3p subshell. Each additional electron in these sub shells represents a different element eg 1 electron, 3s1, corresponds to sodium, 3 electrons, 3s2, 3p1, correspond to aluminium, 7 electrons, 3s2, 3p5, to chlorine.

Answer 2

Because element in period three are atoms which are stable, they contain eight electrons.E.g For an atom to be stable or electrical configuration of an atom which is stable is.2,88....

So an atom like oxygen,aluminum,zinc etc have have electrical configuration of 2,88..

Answer 3

The fourth row/period in the Periodic Table contains 18 elements as this is where the first row of the transition metals appears. These elements have access to the d-orbitals whereas previous elements do not have access to the d-orbitals for filling.

Answer 4

The period equals the number of shells present.

In the first shell there is only one (1x s) orbital. In the second shell there are 4 orbitals present (1x s and 3x p).

Per orbital 2 electrons are acceptable, thus the first period can give place to 2 electrons (which result in two different elements) and the second period has place for 8 electrons (resulting in 8 different elements).

Answer 5

It is because the periodic table is arranged such that each period contains all such elements which have their total no. of electrons falling under a particular shell.

For example: 1st period only has 2 elements because First shell has a max of 2 electrons and only two elements (Hydrogen and Helium) have their total no. of electrons less than or equal to 2.

Answer 6

The periodic 3 elements contain 8 elements because it corresponds to the filling of the 3p and 3s sub-shell which take 8 electrons.

Answer 7

Because the first shell just got space for 2 electrones, while the others got space for more. It's one of these things in the science world you just have to accept without asking why ;)

Answer 8

The seventh period contains 32 elements, most of which are too unstable to be found in nature, All elements of period 7 are radioactive

Answer 9

The elements in the fourth period of the periodic table are: K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, As, Se, Br, Kr.