Answer:
Number of protons = 82
Explanation:
Given data:
Atomic number of Pb = 82
Mass number of Pb-207 = 207
Number of protons = ?
Solution:
An atom consist of electron, protons and neutrons. Protons and neutrons are present with in nucleus while the electrons are present out side the nucleus.
All these three subatomic particles construct an atom. A neutral atom have equal number of proton and electron. The sum of neutrons and protons is the mass number of an atom while the number of protons are number of electrons is the atomic number of an atom.
Atomic number of Pb = number of protons or electrons
82 = number of protons or electrons
Mass number = Number of protons + number of neutron
207 = 82 + number of neutron
Number of neutrons = 207 - 82
Number of neutrons = 125
The trough and the hill part
Awnser: C. petrolium
See, petroleum (i.e. oil) is transformed into gasoline.
"Sometimes, petroleum and crude oil are used to mean the same thing, but petroleum itself is a broad range of petroleum products including crude oil itself. We use the term 'petroleum products after crude oil is refined in a factory." - <span>www.eschooltoday.com/energy/non-renewable-energy/what-is-petroleum.html</span>
Both of you are overlooking a pretty big component of the question...the Group I cation isn't being dissociated into water. We're testing the solubility of the cation when mixed with HCl. And this IS a legitimate question, seeing as our lab manual is the one asking.
<span>By the way, the answer you're looking for is "Because Group I cations have insoluble chlorides". </span>
<span>"In order...to distinguish cation Group I, one adds HCl to a sample. If a Group I cation is present in the sample, a precipitate will form." </span>
