Answer:
<em>The correct option is B) two liquids are mixed at room temperature and a gas forms.</em>
Explanation:
A chemical change can be described as a change which results in the formation of a new substance by the reactants. In the option B, two liquids react to form a new product which is a gas. Hence, it is an example of chemical change.
Other options,like option D, is not a chemical change as by crushing a solid no new product is formed. Option C is also not correct because as when salt dissolves in water, no new product is made.
The atomic mass is the average mass of all the isotopes. The atomic number is the number of protons in the nucleus of an atom. In an uncharged atom the atomic number is also equal to the number of electrons.
Hope this helps!
<span>fossil fuels are mainly organic compounds.Combustion of fossil fuels also produces other air pollutants, such as nitrogen oxides, sulfur dioxide, volatile organic compounds and heavy metals.so,substances which contain sulphur cause to form harmful acids like sulphuric and sulphurus acids</span>
Answer:
Option (2)
Explanation:
Cohesion is usually defined as the contrasting property by which the water molecules are attached to one another, and adhesion is the property by which the molecular substances are linked to the molecules of other substances.
Since, the water molecules are able to form inter-molecular hydrogen bonding, so they are comprised of strong cohesive force.
And, as the water molecules are able to stick to the walls of the container, so they tend to show more of the properties for adhesion.
Thus, according to the given condition, water molecules are sticking to other substances and this is the property of adhesion.
Hence, the correct answer is option (2).
