chembio

What is the atomic number of carbon?

• a) 6
  

• b) 8
  

• c) 12
  

• d) 14

Which of the following is an example of an ionic bond?

• a) H2

• b) NaCl

• c) O2

• d) CH4

What is the molecular formula of glucose?

• a) C6H12O6

• b) C12H22O11

• c) C2H6O

• d) CH4

• Which element is essential for the production of thyroid hormones?

• • a) Iron

• • b) Calcium

• • c) Iodine

• • d) Potassium

What is the pH of pure water?

• a) 5

• b) 7

• c) 9

• d) 11

• Which of the following is a noble gas?

• • a) Oxygen

• • b) Nitrogen

• • c) Helium

• • d) Hydrogen

What is Avogadro's number?

• a) 6.022 x 10^23

• b) 3.141 x 10^7

• c) 9.81 x 10^2

• d) 2.718 x 10^3

Which compound is known as the "universal solvent"?

• a) Ethanol

• b) Benzene

• c) Water

• d) Acetone

Which of the following is an endothermic reaction?

• a) Combustion of wood

• b) Freezing of water

• c) Melting of ice

• d) Condensation of steam

What is the main component of natural gas?

• a) Ethane

• b) Propane

• c) Methane

• d) Butane