An atom contains 8 protons, 8 neutrons and 10 electrons. A second atom contains 9 protons, 10 neutrons and 10 electrons. What can be said about
these two atoms?
A. Both atoms are neutral
B. The atoms are isotopes of each other
C. Both atoms are ions
D. these atoms cannot exist in nature

we can conclude that the melting point of table salt is above room temperature (it's actually 801 deg c). the melting point of mercury must be below room temperature (- 39 deg c).

plasma is the state of matter where the substance is ionized and has no definite shape or volume. the fact of being ionized makes the substance a good electrical conductor.

i don't see a text, but i am gonna assume this *orbit* the curved path, usually elliptical, described by a planet, satellite, spaceship, etc., around a celestial body, as the sun.