The nucleus of an atom has 5 protons and 6 neutrons. What would be the (a) atomic number, (b) mass number, (c) the number of electrons, and (d) the number of valence electrons, per atom of this element?

Q. An atom of an element contains $13$ electrons. Its nucleus has $14$ neutrons. Find out its atomic number and approximate atomic mass. An isotope has atomic mass $2$ units higher. What will be the number of protons, neutrons and electrons in the isotope?

Q. Which of the following statement is always correct?

(a) an atom has equal number of electrons and protons

(b) an atom has equal number of electrons and neutrons

(c) an atom has equal number of protons and neutrons

(d) an atom has equal number of electrons, protons and neutrons

Q. Question 17
Which of the following statement is always correct?

(a) An atom has equal number of electrons and protons
(b) An atom has equal number of electrons and neutrons
(c) An atom has equal number of protons and neutrons
(d) An atom has equal number of electrons, protons and neutrons

Q.

Fill in the blanks in the following statements :

(a) The number of protons in the nucleus of an atom is called its ....................

(b) The total number of protons and neutrons in the nucleus of an atom is called its ....................

(c) An atom has atomic mass number 23 and atomic number 11. The atom has .................... electrons.

(d) An atom of an element has 11 protons, 11 electrons and 12 neutrons. The atomic mass of the atom is ....................

(e) If the nucleus of an atom has atomic number 17, mass number 37 and there are 17 electrons outside the nucleus, the number of neutrons in it is ....................

(f) Almost all the mass of an atom is concentrated in a small region of space called the ....................

(g) Cathode rays are a beam of fast moving ....................

(h) The anode rays obtained from hydrogen gas consist of particles called ....................

(i) The maximum number of electrons that can be accommodated in L shell are ....................

(j) The maximum number of electrons that can go into the M shell is ....................

(k) The subatomic particle not present in a hydrogen atom is ....................

(l) The electron has .................... charge, the proton has .................... charge, and the neutron has .................... charge.

Q. Question 6
Which of the following are true for an element?
(i) Atomic number = number of protons + number of electrons
(ii) Mass number = number of protons + number of neutrons
(iii) Atomic number = number of protons = number of neutrons
(iv) Atomic number = number of protons = number of electrons

(a) (i) and (ii)
(b) (i) and (iii)
(c) (ii) and (iii)
(d) (ii) and (iv)