Because they have the same number of electrons in the outer shell, they have the same reactivity (they all want to lose/gain a certain amount of electrons to have a full shell of 8), so they have the similar melting, boiling points etc because they all undergo very similar reactions to certain factors so have similar outcomes
An orbital is the most probable location of an electron. This is because you can't pinpoint the exact location of an electron because as soon as you do it will have moved again, so orbitals are used to find the probability of where a certain electron is.
Answer:
Atomic #: 82
Mass #: 206
Charge: 4+
# of protons: 82
# of electrons: 78
# of neutrons: 124
Explanation:
Atomic #: look at the bottom left #, it's always the atomic #.
Mass #: look at the top left # it's always the mass #.
Charge: they give you the charge which is shown on the upper right of the element.
# of protons: is the atomic #
# of electrons: also the atomic # minus 4 bc the charge is a positive 4, indicating that some electrons 'left'.
# of neutrons: 206 (mass # is protons + neutrons) minus 82 (atomic#) which is 124.
C.
It is the only thing that is making a new thing, and not breaking or taking apart something that is already there.