this is a very hard question
Answer:
C-18
Explanation:
Step one follow order of operations
Add and subtract from left to right(-5)+(7)=2-(-4)+(12)
STEP 2
Apply negative Rule -(-4)=+4=2+4+(12)
then add 2+4+12=18
Answer:
Answer: Chemical change; Chemical property of heat of combustion
Explanation:
A physical change is defined as a change in which there is alteration in shape, size etc. No new substance gets formed in these reactions.
Explanation:
Answer: Heat dissipation mechanism
Explanation: Heat dissipation mechanism is a thermoregulatory response in humans whereby the hypothalamus of the brain initiates certain processes to reduce the high body temperature. Eg, sweating is initiated which helps cool down the body temperature, also superficial arteries are dilated, thereby leading to flushing and decreasing heatloss into the air. And metabolic heat production is also reduced.