Q: What type of gases are the least reactive of all elements? Choices: - brave - humble - lucky - noble A:
noble

Q: What occurs when some substances change chemically to other substances? Choices: - toxic reaction - spontaneous mutation - hormonal reaction - chemical reaction A:
chemical reaction

Q: German doctor rudolf virchow first discovered what process when studying living cells under a microscope? Choices: - radiation - evolution - photosynthesis - cell division A:
cell division

Q: When zinc reacts with hydrochloric acid, the reaction bubbles vigorously as which type of gas is produced? Choices: - chlorine - oxygen - nitrogen - hydrogren A:
hydrogren