Question

Hi, help with these two questions.

1. Write the isotope notation for an atom with 9 protons and an atomic mass of 20.

2. Write the isotope notation for an atom with 13 protons and 12 neutrons.

Answer 1

Answered below

Step-by-step explanation:

1) Atomic number is usually the number of protons

Since the atom is a neutral atom, Number of protons is equal to the number of electrons.

Thus means that we have 9 electrons and our atomic number is 9.

Atomic mass number is given as 20.

The is topic notation makes use of the atomic number and mass number.

Atomic number of 9 denotes fluorine.

Thus, the isotopic notation is written as attached;

2) we are told that an atom has 13 protons and 12 neutrons.

Similar to A above,

Atomic number is 13.

Now, number of neutrons + number of protons = mass number.

Thus;

Mass number = 13 + 12 = 25

Element with atomic number of 12 is magnesium

Thus,isotopic notation is as attached.