Chemistry Quiz

Atoms of which two elements have a combined total of 23 protons?

• Sodium (Na) and Magnesium (Mg)

• Boron (B) and Carbon (C)

• Copper (Cu) and Zinc (Zn)

• None of these

All of the following are physical properties of chlorine except that chlorine -

• reacts to create compounds with sodium.

• has a density of 3.2 g/L.

• is a yellow-ish green color as a gas.

• is a gas at room temperature.

An atom of chlorine is discovered with a mass number 35. What is the total number of protons, neutrons, and electrons in that atom?

• 35

• 52

• 18

• 17

Which of the following explains why chlorine is a highly reactive element?

• It has 17 protons.

• It has a density of 3.2 g/L.

• It has 7 valence electrons.

• It is green-ish yellow.

Which particle has the least mass?

• a proton

• a helium atom

• an electron

• a hydrogen atom

For an investigation a teacher dropped a bolt into a container of maple syrup. Which of the following physical properties determines why the bolt sinks to the bottom of the beaker?

• mass

• density

• volume

• reactivity

A scientist performs tests on a sample of an element. The element is a shiny solid that conducts electricity and heat. The scientist is able to bend and flatten the sample when pressure is applied to it. Based on this information, the element could not be a member of which group on the periodic table?

• Group 2

• Group 8

• Group 12

• Group 18

For a laboratory investigation some students put a strip of shiny metal into a beaker of blue solution and then stored the beaker on a shelf overnight. The next morning, the students recorded observations about the metal and the solution in the box below. Students' Observations: - The solution is lighter in color. - The volume of solution is the same. - The metal strip is shiny above the surface of the solution. - The metal strip is not shiny below the surface of the solution. - The metal strip below the surface of the solution has a dark coat of flaky material. - When the metal strip is touched, the flaky material falls off. Based on their observations, can the students correctly conclude that a chemical reaction occurred?

• no, because the metal strip was still visible

• yes, because a new material of a different color formed on part of the metal strip

• no, because the solution stayed blue

• yes, because the volume of the blue solution stayed the same

Both the esophagus and the small intestine are involved in the digestion of food. The esophagus squeezes food into the stomach by wave-like muscle contractions. Peptidase enzymes in the small intestine break food molecules into smaller molecules. Which statement best describes changes to food during digestion?

• The muscle contractions result in physical changes, while the action of the peptidase results in chemical changes.

• The muscle contractions and the action of the peptidase both result only in physical changes.

• The muscle contractions result in chemical changes, while the action of the peptidase results in physical changes.

• The muscle contractions and the action of the peptidase both result only in chemical changes.

Mr. Bischoff gives his students four different samples and asks students to determine which of the samples is cobalt. Cobalt has a density of 8.86 g/cm³. Which of the samples above is likely cobalt?

• Sample 1

• Sample 2

• Sample 3

• Sample 4