Question

and electrical charge
there are two properties of protons, neutrons and electrons
that are especially important:

• mass
• electrical charge.

particle	mass	charge
neutron	1	0
electron	a	-1

the atoms of an element contain _______________

Explanation:

Step1: Recall particle mass ratios

Protons and neutrons have a mass of approximately 1 atomic mass unit (amu), while electrons have a much smaller mass (about 1/1836 of a proton's mass, often approximated as 0 for simplicity in basic models).

Step2: Determine electron's mass value

From the table, protons and neutrons have mass "1", and electrons have a mass much smaller, typically represented as 0 (or a very small fraction, but in this context, the placeholder "a" should be 0 based on atomic particle mass knowledge).

Answer:

0 (or in the table's context, the value for electron's mass "a" is 0, as electrons have negligible mass compared to protons/neutrons)