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.
Answer:
Current, I = 8 A
Explanation:
We have,
Voltage, V = 160 V
Resistance, R = 20 ohms
It is required to find the current. The relation between current, voltage and resistance is called Ohm's law. It is given as :

I = current

So, the value of current is 8 A.
The bonds of a glucose molecule store chemical energy