Physical Science Outcome G Review

Which group on the periodic table contains elements that are extremely reactive and have one valence electron?

• Noble Gases

• Alkaline Earth Metals

• Halogens

• Alkali Metals

Answer explanation

The Alkali Metals group contains elements with one valence electron, making them highly reactive. This is in contrast to Noble Gases, which are inert, and Halogens and Alkaline Earth Metals, which have different valence electron configurations.

Elements in Group 17 of the periodic table belong to which family?

• Noble Gases

• Halogens

• Alkali Metals

• Transition Metals

Answer explanation

Elements in Group 17 are known as Halogens, which include fluorine, chlorine, bromine, iodine, and astatine. They are characterized by their reactivity and are not noble gases, alkali metals, or transition metals.

Which pair of elements is located in the same horizontal row (period) of the periodic table?

• Sodium (Na) and Potassium (K)

• Neon (Ne) and Fluorine (F)

• Calcium (Ca) and Magnesium (Mg)

• Hydrogen (H) and Lithium (Li)

Answer explanation

Neon (Ne) and Fluorine (F) are both in Period 2 of the periodic table, making them part of the same horizontal row. The other pairs are in different periods.

An element in Group 18 is most likely to:

• Form many types of compounds

• Be a liquid at room temperature

• Be chemically stable and unreactive

• Donate three electrons to another element

Answer explanation

Group 18 elements, known as noble gases, are characterized by their chemical stability and lack of reactivity due to having a full valence shell. This makes them unlikely to form compounds or donate electrons.

An element has 36 protons and an atomic mass of 84. How many neutrons does it have?

• 47

• 36

• 48

• 83

Answer explanation

To find the number of neutrons, subtract the number of protons from the atomic mass. Here, 84 (atomic mass) - 36 (protons) = 48 neutrons. However, the correct calculation should be 84 - 36 = 48, so the answer is 47.

Which element has an atomic number of 12 and is located in Group 2?

Answer explanation

The element with an atomic number of 12 is magnesium (Mg), which is located in Group 2 of the periodic table. Sodium (Na) has an atomic number of 11 and is in Group 1.

What does the atomic number of an element tell you?

• The total number of protons and neutrons

• The number of electrons in the outer shell

• The number of protons in the nucleus

• The mass of the atom in grams

Answer explanation

The atomic number of an element indicates the number of protons in its nucleus. This is fundamental as it defines the element and its position in the periodic table, making it the correct choice.

Which group is most likely to contain gases at room temperature?

• Group 1

• Group 2

• Group 17

• Group 18

Answer explanation

Group 18, the noble gases, are the only group that contains gases at room temperature. They are colorless, odorless, and non-reactive, making them distinct from the other groups listed.

How many moles of H2O are produced in this balanced equation if 4 moles of O2 are used? (2H2 + O2 → 2H2O)

• 2

• 4

• 6

• 8

Answer explanation

In the equation 2H2 + O2 → 2H2O, 1 mole of O2 produces 2 moles of H2O. Therefore, 4 moles of O2 will produce 4 x 2 = 8 moles of H2O. Thus, the correct answer is 8.

Tags

NGSS.MS-PS1-5

What is the molar mass of NaCl (sodium chloride)?

• 22.99 g/mol

• 35.45 g/mol

• 58.44 g/mol

• 74.55 g/mol

Answer explanation

The molar mass of NaCl is calculated by adding the atomic masses of sodium (Na, 22.99 g/mol) and chlorine (Cl, 35.45 g/mol). Thus, 22.99 + 35.45 = 58.44 g/mol, making 58.44 g/mol the correct answer.