Answer:
Hydrogen(H) and Heluim(He)
Explanation:
These are the only two valennce electrons and 1 energy levels.
The state of matter is liquid.
The most common hydrogen carbon fuels are ethanol and diesel and their product of combustion is carbon dioxide, water and heat .
Answer:
Four electrons are present in the valence shell of Silicon.
Explanation:
Valence shell electrons are those electrons which are present in the outermost shell of an atom. These valence shell electrons are responsible for in the formation of bonds with other atoms.
Silicon having atomic number 14 has fourteen electrons in its neutral state and has the electronic configuration as follow;
1s², 2s², 2p⁶, 3s², 3p²
In given configuration the valence shell (outermost shell) is 3 and the number of electrons present in it are four i.e. 3s² and 3p² (2 + 2 = 4) respectively.
Relative energies are in the order:
s < p < d < f
And the shape of these orbitals are
s - spherical
p - dumbbell
d - double dumbbell
f - double double dumbbell
