World Book Trivia Challenge Advanced-5/22-chemical Elements

1. What is the symbol for the compound of salt?

NaCa

NaCl

NaC

Soda is the common name for a group of compounds that contain sodium. These sodium compounds are manufactured from common salt (NaCl), which is made up of sodium and chlorine.

Explanation

Soda is the common name for a group of compounds that contain sodium. These sodium compounds are manufactured from common salt (NaCl), which is made up of sodium and chlorine.

2. What element has the symbol of K?

Potassium

Chlorine

Krypton

The chemical symbol of potassium is K. Potassium belongs to the group of elements called alkali metals

Explanation

The chemical symbol of potassium is K. Potassium belongs to the group of elements called alkali metals

3. The largest percentage of the periodic elements are what?

Noble gases

Actinides

Metals

Metal is any of a large group of chemical elements that includes copper, gold, iron, lead, silver, tin, and other elements that share similar qualities. Nearly 80 percent of the known elements are metals.

Explanation

Metal is any of a large group of chemical elements that includes copper, gold, iron, lead, silver, tin, and other elements that share similar qualities. Nearly 80 percent of the known elements are metals.

4. What is a substance containing more than one element, but does not have the fixed ratio of a compound?

Mixture

Addition

Combination

Many substances that contain atoms from more than one element are mixtures, not compounds. A compound always has the same composition by weight. However, the composition of a mixture is not fixed and varies from sample to sample. For example, chocolate chip ice cream is a mixture. Its composition varies, and some samples contain more chocolate chips than others.

Explanation

Many substances that contain atoms from more than one element are mixtures, not compounds. A compound always has the same composition by weight. However, the composition of a mixture is not fixed and varies from sample to sample. For example, chocolate chip ice cream is a mixture. Its composition varies, and some samples contain more chocolate chips than others.

5. What is the lightest known metal?

Lithium

Zirconium

Dubnium

Lithium, «LIHTH ee uhm», is a soft, silvery-white metallic element, the lightest known metal

Explanation

Lithium, «LIHTH ee uhm», is a soft, silvery-white metallic element, the lightest known metal

6. Which of the following is NOT a noble gas?

Helium

Krypton

Carbon

Noble gas refers to any of a group of six chemical elements. These elements are argon (Ar), helium (He), krypton (Kr), neon (Ne), radon (Rn), and xenon (Xe).

Explanation

Noble gas refers to any of a group of six chemical elements. These elements are argon (Ar), helium (He), krypton (Kr), neon (Ne), radon (Rn), and xenon (Xe).

7. How many recognized elements are there?

108

114

121

The International Union of Pure and Applied Chemistry (IUPAC) is the recognized authority in crediting the discovery of elements and assigning names to them. For a discovery to be recognized by IUPAC, scientists must produce a sample of the element and measure certain of its properties. In addition, IUPAC prefers that another experiment confirm the discovery. IUPAC recognizes the existence of 114 elements. Scientists have also claimed the discovery of several other elements.

Explanation

The International Union of Pure and Applied Chemistry (IUPAC) is the recognized authority in crediting the discovery of elements and assigning names to them. For a discovery to be recognized by IUPAC, scientists must produce a sample of the element and measure certain of its properties. In addition, IUPAC prefers that another experiment confirm the discovery. IUPAC recognizes the existence of 114 elements. Scientists have also claimed the discovery of several other elements.

8. What are the vertical columns in the periodic table called?

Periods

Groups

Columns

The periodic table lists the elements in horizontal rows, called periods, in order of increasing atomic number. Elements that have similar properties lie in vertical columns called groups.

Explanation

The periodic table lists the elements in horizontal rows, called periods, in order of increasing atomic number. Elements that have similar properties lie in vertical columns called groups.

9. What is the most plentiful element in Earth's crust?

Oxygen

Silicon

Hydrogen

Oxygen and silicon are the most plentiful elements in Earth's crust, accounting for about 47 percent and 28 percent of the crust's mass (amount of matter), respectively.

Explanation

Oxygen and silicon are the most plentiful elements in Earth's crust, accounting for about 47 percent and 28 percent of the crust's mass (amount of matter), respectively.

10. If you gave the flame test to the K element, what color would it produce?

Crimson

Greenish

Violet

Flame test is a way of identifying a chemical element by the color of the light it gives off when held in a flame. For most elements, the test can be made by dipping a platinum wire in a compound of the element, either powdered or in solution. The wire is then held in the flame of a Bunsen burner (see Bunsen burner).
An element always gives off flame of the same color. For example, compounds of barium color the flame yellowish green. Flames of calcium are orange-red. Copper gives off an emerald-green color. Lithium's flame is deep red. Sodium's flame is yellow. Strontium gives off a crimson flame. Potassium's flame is violet.

Explanation

Flame test is a way of identifying a chemical element by the color of the light it gives off when held in a flame. For most elements, the test can be made by dipping a platinum wire in a compound of the element, either powdered or in solution. The wire is then held in the flame of a Bunsen burner (see Bunsen burner).
An element always gives off flame of the same color. For example, compounds of barium color the flame yellowish green. Flames of calcium are orange-red. Copper gives off an emerald-green color. Lithium's flame is deep red. Sodium's flame is yellow. Strontium gives off a crimson flame. Potassium's flame is violet.