atomic number - Free Student Notes

An atom of an element has an atomic number of 9 and a mass number of 19:

(a) State the number of protons and neutrons in the nucleus of this atom. The atomic number tells us the number of protons in the atom. For an atom with an atomic number of 9, there are 9 protons. The mass number is the sum of the protons and neutrons. Therefore, the number of neutrons … Read more

The atomic number of an element is 23, and its mass number is 56.

(a) How many protons and electrons does an atom of this element have? Protons: The atomic number is 23, so it has 23 protons. Electrons: In a neutral atom, the number of electrons equals the number of protons, so it has 23 electrons. (b) How many neutrons does this atom have? Neutrons = Mass number … Read more

Define atomic number, atomic mass number, and nucleon number. How is an atom represented symbolically? Find the number of protons, neutrons, atomic number, atomic mass number, and nucleon number from X. Which element is this?

Atomic Number (Z): The atomic number of an element is the number of protons in the nucleus of an atom. It determines the element’s identity and its position in the periodic table. Atomic Mass Number (A): The atomic mass number (also called mass number) is the total number of protons and neutrons in an atom’s … Read more