The atomic number or proton number (symbol Z) of a chemical element is the number of protons found in the nucleus of an atom. It is identical to the charge number of the nucleus. The atomic number uniquely identifies a chemical element. In an uncharged atom, the atomic number is also equal to the number of electrons.
Answer:
option a
Explanation:
Size of an atom (diameter) = 10⁻¹⁰ m
There are approximately 10²² atoms in a single drop of water. If they are put in a straight line, the length would be
l = diameter of an atom × number of atoms
l = 10²²× 10⁻¹⁰ m = 10¹² m
Distance between the Sun and the Earth is 1.47 × 10¹¹ m. The calculated length is greater than the distance between the Sun and the Earth.
Thus, option a is correct.
d 30 minutes a day , 5 days a week
