The diagram shows four different locations in an atom.

Question

A shaded circle is shown, labeled nucleus. Two small points labeled two and three are shown inside this shaded circle. A lighter shaded concentric circle is shown with a radius more than double of the radius of the inner circle. A point labeled one is shown inside a section of this circle which does not overlap with the inner circle. A flower petal like shaded region is shown above and below these circles. A point labeled four is shown inside the lower petal.

Which locations are likely to have subatomic particles with the greatest mass?

1 and 2
2 and 3
1 and 4
3 and 4

Answer 1

In an atom, subatomic particles with the greatest mass are the protons and neutrons, which are located in the nucleus.

From your description:

• The shaded circle labeled "nucleus" contains the points labeled 2 and 3, which indicates that these points are inside the nucleus where protons and neutrons reside.

The other points (1 and 4) are outside the nucleus:

• Point 1 is in a lighter shaded concentric circle (the electron cloud or orbital).
• Point 4 is also in a region outside the nucleus (indicated as a "petal" shaped area).

Since the protons and neutrons are the heaviest particles and are found in the nucleus, the locations that are likely to have subatomic particles with the greatest mass are:

2 and 3.