Video Transcript
What is the correct pairing of the
terms and descriptions shown in the boxes below? (A) 1C, 2A, 3B; (B) 1A, 2B, 3C; (C)
1B, 2A, 3C; (D) 1B, 2C, 3A; (E) 1A, 2C, 3B.
Let’s start by looking at an
atom. This is an atom of deuterium, an
isotope of hydrogen. This atom has one neutron, one
proton, and one electron. Neutrons are neutral, protons have
a positive charge, and electrons have a negative charge. As an atom has the same number of
positively charged protons and negatively charged electrons, it is neutral
overall. So, an atom is an electrically
neutral particle with an equal number of electrons and protons.
Now, let’s look at what happens
when a hydrogen atom gains one additional electron. Now there’s one neutral neutron,
one positively charged proton, and two negatively charged electrons. This species has an overall
negative charge and is called a negative ion. So, a charged particle that has a
greater number of electrons than protons is a negative ion. But what happens to a hydrogen atom
if it loses an electron? This species has one neutral
neutron and one positively charged proton, but no negatively charged electrons. So, this species has an overall
positive charge and is called a positive ion. So, a charged particle that has a
smaller number of electrons than protons is called a positive ion.
In conclusion, the correct pairing
of the terms and descriptions shown in the boxes below is answer choice (D): 1B, 2C,
3A.
