Ions are formed by the addition of electrons to, or the removal of electrons from, neutral atoms or molecules or other ions; by combination of ions with other particles; or by rupture of a covalent bond between two atoms
Answer:
The famous oil drop experiment exploits that fact that an oil drop in an electronic field will get negative charge accumulation which can be balanced and observed in order to determine the charge of an electron.
For which of the following activities might you want to hire a chemist?
Answer: D. testing a rock sample for gold content
Which of the following procedures involves a physical change in one of the substances?
Answer: C. separating a salt solution by evaporating the water
Answer:
It's the second one down.
Explanation:
Gold
Mass 197
Number of Protons: 79
Number of Neutrons: 197 - 79 = 118
Number of electrons: = number of protons = 97
The noble gases are relatively unreactive because they have a stable octet of valence electrons.
Thus, they do not tend to undergo reactions in which they will gain or lose valence electrons,
However, <em>only He, Ne, and Ar are inert</em>. Kr and Xe combine with other highly reactive elements to form stable compounds.