Question

The nuclear symbol of an isotope of beryllium is . Indicate the number of protons, number of neutrons, atomic number, and mass number of the isotope.

Answer 1

Step-by-step explanation:

An isotope is any of two or more forms of an element where the atoms have the same number of protons, but a different number of neutrons within their nuclei.

As a consequence, atoms for the same isotope will have the same atomic number but a different mass number (atomic weight).

In the figure below we see three isomers of Beryllium.

Mass number = proton + neutron

Proton number = atomic number

Mass number – the total number of protons and neutrons in an atomic nucleus.

Atomic mass – the number, equal to the number of protons in an atom that determines its chemical properties. Symbol: Z

Answer 2

^9Be (superscript 9 Be)

It has 4 protons, 5 neutrons, atomic number 4 and mass number 9.

Step-by-step explanation:

Beryllium (4Be) has 12 known isotopes, but only one of these isotopes (9Be) is stable. As such, beryllium is considered a monoisotopic element.

From the symbol of the isotope, the mass number is generally 9.

Also having atomic number 4 shows the proton number is 4.

Using

mass number = proton + neutron

Therefore neutron = 9 - 4 = 5.

It has 5 neutrons.