Chemistry Midterm Review

Using the periodic table, predict which elements will have similar chemical properties or reactivity.

• cadmium, calcium, and carbon

• magnesium, strontium, and barium

• rubidium, yttrium, and zirconium

• nitrogen, sulfur, and bromine

How many electrons would there be in a sulfur ion atom if there were 34 neutrons, 16 protons, and it gained an extra 2 electrons?

• 18

• 16

• 32

• 52

In the number 12.030, the correct number of significant figures is-

• 3

• 5

• 4

• 2

Who created the plum pudding model?

• Dalton

• Thomson

• Rutherford

• Bohr

Answer explanation

Properties like reactivity, flammability, color, taste and density are all independent from the amount of matter present. All of these properties are examples of:

• chemical properties

• physical properties

• intensive properties

• extensive properties

Imagine that a new element was discovered. This element shows very little reactivity with any other element on the Periodic Table, and it exists as a gas at room temperature. Which group would be the best classification for this new element?

• alkali metals

• halogens

• transition metals

• noble gases

1.      Naturally occurring chlorine that is put in pools is 75.53 percent ³⁵Cl and 24.47 percent ³⁷Cl. What is the average atomic mass for chlorine?

• 17.74 amu

• 35.49 amu

• 36.00 amu

• 36.58 amu

In moving down a group of the Periodic Table, ionization energy-

• remains constant

• increases

• decreases

When is an atom considered electrically neutral (no charge)?

• neutrons equal the number of protons

• proton forces pull on the neutrons

• electrons equal the number of protons

• electrons equal the number of neutrons

Henry Moseley studied x-ray spectra of several elements in a row of the periodic table. He found that each element had one more proton than the element immediately to its left. Which statement BEST describes Moseley's contribution to the modern periodic table?

• Recognizing that elements in the periodic table have similar properties

• Arranging elements in the periodic table based on their properties

• Predicting the properties of missing elements in the periodic table

• Providing a basis for ordering elements in the periodic table based on atomic number