Answer:
256.
Explanation:
If a bacterium divides once in every half an hour, it means it will double in half an hour. Hence a number of the bacterium after half an hour will be 1×2=2. After one hour the number of bacterium will be 2×2=4. Similarly, it one and a half hours it will be 4×2=8. In two hours it will be 8×2=16 in two and half hours, it will be 16×2=32. In three hours it will be 32×2=64. In three and half hours it will be 64×2=128. Hence, in 4 (four) hours the number of bacterium will be 128×2=256.
The answer is A. They have a hydrocarbon backbone that can be chemically altered.
<span>Synthetic cathinones, more commonly known as "bath salts," are synthetic drugs chemically related to cathinone, a stimulant found in the khat plant. Khat is a shrub grown in East Africa and southern Arabia, and people sometimes chew its leaves for their mild stimulant effects. Synthetic variants of cathinone can be much stronger than the natural product and, in some cases very dangerous. This the correct answer :)</span>
