plzz...ans my question.....
Answers
a-electrons are very lighter than protons and neutrons.
therefore the atomic mass is the sum of protons and neutrons only which are present in the nucleus.
That's why all the mass is concentrated in the nucleus.
b-When an atom is electrically neutral, it means that the overall charge of the atom is zero. Atoms are made up of positively charged particles called protons and negatively charged particles called electrons as well as non-charged particles called neutrons. The charge from a proton or electron are of equal strength, therefore if an atom has an equal number of protons and electrons, it will be electrically neutral. However, atoms are not always electrically neutral, in which case they are called ions. An ion is an atom that has lost or gained electrons resulting in a positive charge (from losing electrons) or a negative charge (from gaining electrons)
c-Atomic number is simply the count of protons in an atom’s nucleus, so it is always a whole number. Atomic mass is NOT a whole number, as it includes the mass of protons, neutrons, and all the other sub-atomic particles in the atom. Generally atomic mass for a given element is stated as the average mass of the atoms of all the isotopes for that element weighted in proportion to relative abundance of the various isotopes as they occur in nature. For any particular isotope the atomic mass is very close to a whole number.
d- because the protons are positively charged