Question

(1)Atomic number of an element is 9 and mass number is 19. (a)Find it's atomic number and mass number. (b)Find number of electrons, protons and neutrons in it. (c)Name element. (d) it's valency. (2)Write electronic configuration of (a)sodium atom (b) sodium ion. (3)Which is bigger in size, sodium atom or sodium ion. (4)Define atomic number. (5)In treatment of which disease isotope of cobalt used. 27 (6) X 13 Write electrons, protons and neutrons in X (7)Name 3 isotopes of hydrogen and their names.. (8)Define isotopes. (9)In which fundamental particle isotopes different. (10)We know carbon has two isotopes. Their mass numbers are 12 and 14. In which fundamental particle do they differ.​

Answer 1

Answer:

An atom has an atomic number of 9 and a mass number of 19. Solution: There are 9 protons because the atomic number is always equal to the number of protons present. There are 10 neutrons because the number of neutrons is always obtained by subtracting the atomic number from the mass number.