Q: What involves the emission of a particle and/or energy as one atom changes into another? Choices: - spontaneous mutation - atomic transformation - enthalpy - radioactive decay A:
radioactive decay

(Question)
Q: What is the measure of how closely molecules are packed together? Choices: - length - volume - frequency - density A:
(Answer)
density

Ques: Q: Which organ is the control center of the nervous system? Choices: - the heart - the spine - the lungs - the brain A:
Ans: the brain

(Q).
Q: In a hot water heater, burning fuel causes the water to get hot because combustion is what type of reaction? Choices: - endothermic - geothermal - biochemical - exothermic A:
(A).
exothermic

Ques:Q: Are vesicles larger or smaller than vacuoles? Choices: - larger - narrower - wider - smaller A:

Ans:smaller

Q: What medical emergency occurs when a blood clot blocks blood flow to part of the brain, causing death of brain cells? Choices: - cardiac arrest - epileptic seizure - heart murmur - stroke A:
stroke