Question

Write sown rhe first 20 name of element with their atomuc number and mass

Answer 1

(1) Hydrogen- atomic no- 1, atomic mass- 1.0079 (2)helium- atomic no- 2, atomic mass- 4.0026 (3) lithium- atomic no-3, atomic mass-6.941 (4)beryllium- atomic no-4, atomic mass-9.0122 (5)boron- atomic no- 5, atomic mass- 10.811 (6)carbon - atomic no-6, atomic mass- 12.011 (7)nitrogen- atomic no-7, atomic mass- 14.007 (8)oxygen- atomic no-8, atomic mass- 15.999 (9) fluorine- atomic no-9, atomic mass- 18.998 (10)neon- atomic no- 10, atomic mass-20.180 (11)sodium - atomic no -11 , atomic mass- 22.990 (12) magnesium- atomic no -12 , atomic mass-24.305 (13) aluminum - atomic no- 13, atomic mass- 26.982 (14) silicon- atomic no- 14, atomic mass- 28.086 (15) phosphorus- atomic no - 15, atomic mass- 30.974 (16) sulphur- atomic no - 16, atomic mass-32.065 (17) chlorine- atomic no- 17, atomic mass- 35.453 (18) argon - atomic no-18, atomic mass-39.948 (19) potassium- atomic no- 19, atomic mass-39.098 (20)calcium- atomic no-20, atomic mass-40.078