Answer:
Here it is (sorry its late)
Explanation:
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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.
Answer:
Selenium
Explanation:
One way to figure this out is to count the electrons and add them up.
2+2+6+2+6+2+10+4 = 34 electrons
A neutral atom has the same number of electrons and protons. Protons tell us the atomic number of an element. Element number 34 is Selenium.
Another way to figure it out is to look at just the highest "s" or "p" level of the electron configuration, and then see which element corresponds to that. This element has a 4s and a 4p, so I will look at 4p. The configuration is 4p4, so I will look at the 4th row of the periodic table (4p4) in the "p" block (4p4) and the 4th element in the "p" block (4p4). That's selenium :)
