Video Transcript
Fill in the blank. A positive ion is an atom that has
blank. (A) Gained one or more
electrons. (B) Gained a proton from its
nucleus. (C) Lost one or more electrons. (D) Lost a proton from its
nucleus. Or (E) an equal number of electrons
and protons.
This question asks us what happens
to an atom when it forms a positive ion. To do this, we must first
understand an atom. Atoms have a positively charged
center called a nucleus. The nucleus contains positively
charged particles called protons. It contains other particles called
neutrons which we will not address in this video. Surrounding the nucleus are
negatively charged particles called electrons. We should note that this diagram is
not drawn to scale.
When atoms are involved in chemical
reactions, electrons are the particles that can be lost or gained. All atoms have both protons and
electrons. In order for an atom to be neutral,
it must have the same number of protons and electrons. This changes when an atom becomes a
positive ion. A positive ion is an atom that has
lost one or more electrons during a chemical reaction.
Let’s look at an example. The atom in our diagram contains
four protons and four electrons. In a chemical reaction, the atom
could lose one electron. This means the atom will only have
three electrons, but it will still have four protons. In positive ions, there are more
protons present than electrons. This causes the atom to become
positively charged overall.
We can see that answer choice (C)
describes what happens to an atom to form a positive ion. We can now fill in the blank. A positive ion is an atom that has
lost one or more electrons.
