Four atoms have the numbers of protons and neutrons given below. Which two atoms are isotopes of the same element? W : 8 protons and 8 neutrons, X : 8 protons and 10 neutrons, Y : 10 protons and 8 neutrons, Z : 9 protons and 10 neutrons

The atomic number of an element is …

Uranium-235 has 92 protons. How many neutrons does it have?

An alpha particle is…

What has an ionised atom lost or gained?

Lithium-6 has 3 protons. How many neutrons does it have?

An atom has 13 protons and 14 neutrons. What is its mass number?

What is nuclear fission?

What is the chemical symbol for the element mercury?

What is the best definition of the mass number of an element?

An atom has an atomic number of 9 and a mass number of 19. What are its numbers of protons, neutrons and electrons?

What is the formula of water?