Chemistry
From the symbol for the element helium, write down the mass number and the atomic number of the element.
Related Questions
Name the element which does not contain any neutrons in it's nucleus.
Elements X, Y, Z have atomic numbers 6, 9 and 12 respectively. Which one :
(i) forms anion – negative ion;
(ii) forms cation – positive ion;
(iii) has 4 electrons in the outermost orbit.
Define the terms : atomic number, mass number and electron.
Sulphur has an atomic number of 16 and a mass number of 32.
State the number of protons and neutrons present in the nucleus of sulphur.