Class IX Ca on loosing 2 electrons becomes Ca-2 Ca-1 Ca+2 Ca-2 Hair contains keratin proteins which are also present in nails and wool is an example of Biochemistry Inorganic chemistry Physical chemistry none of above . Number of atoms of hydrogen in 2 moles of NH3 5 * 1023 3.01 * 1023 3.61 * 1024 4 * 1023 A science that examines material this universe contain and changes in them is called Chemistry Physics Biology Geography Number of protons and neutrons in nucleus if atomic number of element is 17 and mass number is 35, is 17 and 18 17 and 19 17 and 20 17 and 21 Do you really want to submit this quiz? Cancel Submit Quiz
