Answer:
Environment refers to everything that surrounds an individual and interacts between them. The factors that control the environment can be biotic and abiotic.
Humans have greatly affected the environment. Some of the ways in which the environment is affected by humans are as follows-
(1) Humans have constructed industries and factories that have released a huge amount of toxic gases into the atmosphere.
(2) These harmful gases have increased the earth's global temperature. As a result of which the global warming effect has increased.
(3) The waste materials eliminated from these industries mix with the rivers and streams and pollute the water. It degrades water quality.
(4) The fossil fuels are exhausted at a very high rate.
(5) The spilling of the oils in the oceans has affected the marine species drastically.
(6) Due to the extensive mining at different places, soil fertility has decreased considerably.
(7) Cutting down trees for settlement purposes and other infrastructures.
Answer:
C. Solids made of molecules
C2H2 is the right answer I believe
Since protons are postive and neutrons are neutral. Then it is postive.
<u>Answer:</u> The force that must be applied is 15 N.
<u>Explanation:</u>
Force exerted on the object is defined as the product of mass of the object and the acceleration of the object.
Mathematically,

where,
F = force exerted = ?
m = mass of the object = 3 kg
a = acceleration of the object = 
Putting values in above equation, we get:

Hence, the force that must be applied is 15 N.