Chem SOL Review #1

A student measured the mass of a small object and found it to be 56.0 grams. The object's mass is known to be 55.0 grams. What is the percent of error in the student's measurement?

According to the periodic table, which of the following series of elements is ordered according to decreasing reactivity?

Radioactive iodine-131 has a half-life of eight days. The amount of a 200.0 gram sample left after 32 days would be -

The most efficient way to determine whether a reaction is an exothermic chemical reaction is to use -

Which of these laboratory techniques is best to separate a solid from a liquid to recover the liquid?

Each of four groups of students determined and recorded the melting point of a solid compound. If the actual melting point is 113°C, which group had the best precision?

A student is studying the effects of several solutions on the prevention of the browning of apples. The student used solutions having different pH values and immersed three apple slices in equal volumes of each of the solutions. Which of these is the independent variable in this investigation?

Which element has 16 neutrons, 15 protons, and 15 electrons?

While English physicist J. J. Thomson was carrying out experiments on cathode rays, he was able to determine that the rays consisted of particles he called "corpuscles." These particles were later named -

A chemist is examining an unidentified element sample with oxidation states of +2, +3, and +6. The element has a shielding effect similar to that of potassium (K). Which statement about the unidentified element is most likely true?

A student hypothesizes that bromine (Br) has different chemical properties from krypton (Kr). The periodic table supports this hypothesis by indicating that -

A neutral atom of calcium has 20 electrons. Calcium forms a 2+ ion. How many electrons does a calcium ion have?

What are the numbers of protons, neutrons, and electrons in an isotope of titanium with a mass number of 50?

Which of these elements has the smallest atomic radius?

The element chlorine exists as two naturally occurring isotopes. Cl-35 occurs 75% of the time and Cl-37 occurs 25% of the time. Which of the following calculations should be used to calculate the correct average atomic mass of chlorine?