An element’s atomic number is equal to the number of protons in that element’s nucleus. The mass number is the total number of an atom’s protons and neutrons. Protons have a positive charge; electrons have a negative charge; and neutrons are electrically neutral.
Putting it all together, given that the atomic number of lead is 82, the number of protons a lead atom contains is 82. The number of neutrons would be the difference between 207 and 82, or 125 neutrons. Finally, since you have a neutral atom, there must be an equal number of electrons as the number of protons—that is, 82 electrons.
Thus, you’ve got 82 protons, 125 neutrons, and 82 electrons.
Examination by a test; experiment, as in chemistry, metallurgy, etc.
Answer:
An addition reaction
Step-by-step explanation:
In an addition reaction, two or more molecules come together to form a single product, for example,
C₂H₂ + 2Cl₂ ⟶ C₂H₂Cl₄
This reaction consists of two successive additions. The product of the first reaction becomes a reactant and adds a second molecule of Cl₂ to form C₂H₂Cl₄
C₂H₂ + Cl₂ ⟶ <em>C₂H₂Cl₂
</em>
<em><u>C₂H₂Cl₂</u></em><u> + Cl₂ ⟶ C₂H₂Cl₄
</u>
C₂H₂ + 2Cl₂ ⟶ C₂H₂Cl₄
Answer:
magnesium chloride: MgCl2
zinc sulphide: ZnS
sodium sulphate: Na2SO4
calcium bicarbonate: Ca(HCO3)2
Which type of telescope is most useful for detecting a star that emits very long electromagnetic waves?
A. a radio telescope B. an X-ray telescope C. an optical telescope D. a gamma ray telescope
A.)a radio telescope
