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.
Explanation:
Because when you move the decimal point once, it it equal to 10 and to convert in the metric system, you must multiply or divide by 10. For example, when converting 4 centimeters to millimeters, you can multiply by 10 to get 40 millimeters or you can move the decimal point to the right and add another 0 to get 40.
Answer:
CH3
|
CH3- C H -CH2-CH2- CH - CH2-CH2-CH3
|
CH
/ \
CH3 CH3
Explanation:
Octan
C-C-C-C-C-C-C-C
Metyl
CH3 -
Isopropyl
CH3
/
- CH
\
CH3
2-metil-5-isopropiloctan
CH3
|
CH3- C H -CH2-CH2- CH - CH2-CH2-CH3
|
CH
/ \
CH3 CH3
No, the elements are not always transparent.
<u>Explanation:</u>
The elements become transparent when the light passes through those elements. Transparency is caused because of the transmission and the passing of the light waves through these elements.
But the metals do not become transparent even when the light waves pass through these metals. Metals do not become transparent because the refractive index in them is very big.
