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: Temperature is an example of a quantitative variable
Explanation:
A quantitative variable is defined as :
- A variable that can assume a numerical value .
- It can be ordered with respect to either magnitude or dimensions.
- It is further classified into two types : interval scale and ratio scale.
Temperature comes under interval scale , because interval scale has no zero point.
For example : A 0° C Celsius does not interpret that there is no temperature.
Therefore , Temperature is an example of a quantitative variable.
Hence, the correct answer is "quantitative variable"
Answer:
The answer is 20 % V/V
Explanation:
We use this formula for calculate the %V/V:
%V/V= (ml solute/ml solution) x 100= (75ml/375 ml)x 100 = 20 % V/V
<em>The% V / V represents the amount of ml of solute dissolved in 100 ml of solution</em>
Explanation:
“The isomers butane and methyl propane have the same molecular formula and different properties”, this is because structural isomers usually have different properties to their parent.
Nuclear reaction: ¹¹C → ¹¹B + e⁺(positron) + ve(electron neutrino).<span><span><span><span>
</span></span></span></span>Beta
decay is radioactive decay<span> in which
a beta ray and a neutrino are emitted from an atomic
nucleus.
There are two types of beta
decay: beta minus and beta
plus. In beta minus decay, neutron is converted to a
proton and an electron and
an electron antineutrino and in beta
plus decay, a proton is converted to a neutron and positron and an electron neutrino, so mass number does not change.</span>