Lead is a basic metal and almost 11 isotopes of Lead are reported. The isotopes with greater natural abundance are as follow;
1) ²⁰⁸Pb with abundance 52.4 %
2) ²⁰⁶Pb with abundance 24.1 %
3) ²⁰⁷Pb with abundance 22.1 %
4) ²⁰⁴Pb with abundance 1.4 %
Molar mass of ²⁰⁸Pb:
Molar mass of any element is the total of number of protons, neutrons and electrons.
As, number of protons in Lead are 82 then in ²⁰⁸Pb isotope number of neutrons are...
# of Neutrons = M.mass - # of protons
# of Neutrons = 208 - 82
# of Neutrons = 126
Result:
Molecular Mass of Lead (²⁰⁸Pb) is 208 amu.
# of Protons in ²⁰⁸Pb = 82
# of Neutrons in ²⁰⁸Pb = 126
The correct answers are options C, that is, silver tarnishes and becomes black when exposed to oxygen, and option E, that is, diesel fuel burns when it is heated.
Chemical changes refer to the modifications in which the chemistry at molecular level is modified as the initial substance gets transformed into a new and different final substance. This change occurs with the dissociation of old bond and production of new bonds respectively.
Silver gets tarnished and becomes black when exposed to oxygen. This refers to a chemical change as silver a white and lustrous substance gets transformed into a tarnish black final substance. However, silver does not easily react with oxygen at usual circumstances. It easily reacts with sulfur comprising components in the air and generates black compound as Ag₂S.
Burning of diesel fuel when it is heated. Diesel refers to a mixture of hydrocarbons varying approximately from C₁₀H₂₀ to C₁₅H₂₈. When these hydrocarbons get burnt they generate novel substances, that is, carbon dioxide and water. Hence, it is also a chemical reaction.
<span>According to octet rule, atoms with an atomic number less than 20 tend to combine with other atom such that both of these atoms have eight electrons in their valence shells, which gives them the same electronic configuration as that of noble gas.
However, there are few compound that donot obey octel rule. Among the elements mentioned above i.e. oxygen and helium obeys octet rule.
In case of nitrogen, oxide of nitrogen (like NO and NO2) have incomplete octet.
While there are few compounds of Br wherein Br has expanded octet. For example, in BrF5, Br has 12 electrons in valence shell. </span>
The answer is 9.5 one as it is more basic so it contains more OH ion
Hope it helps : )
Answer:
Explanation:
Examples of applied chemistry include creation of the variety of laundry detergents on the market and development of oil refineries.
