7th Grade Science: Periodic Table (7.PS1.5)

In which area of the periodic table are transition metals located?

• area 1

• area 2

• area 3

• area 4

Answer explanation

Transition metals are located in area 2 of the periodic table, specifically in groups 3 to 12. They are characterized by their ability to form variable oxidation states and complex ions.

Which image of the periodic table shows the correct shading of the region which has the most reactive elements?

• A

• B

• C

• D

Answer explanation

Choice D correctly highlights the region of the periodic table where the most reactive elements are found, specifically the alkali metals in Group 1 and the halogens in Group 17, which are known for their high reactivity.

Calcium is a metal that can form compounds with certain nonmetals. Which element in the portion of the periodic table shown will be the most reactive with calcium?

• arsenic

• boron

• chlorine

• lead

Answer explanation

Chlorine is a highly reactive nonmetal that readily forms ionic compounds with metals like calcium. In contrast, arsenic, boron, and lead are less reactive with calcium, making chlorine the most reactive choice.

Tags

NGSS.MS-PS1-2

Select all of the elements that are classified as metals.

• gold

• helium

• sodium

• aluminum

• sulfur

Answer explanation

Gold, sodium, and aluminum are classified as metals due to their properties such as conductivity and malleability. Helium is a noble gas, and sulfur is a non-metal, making them incorrect choices.

During an activity, a teacher takes a connecting wire of a simple electric circuit and cuts it open. She shows the material inside the wire to her class. What material should be used to make the connecting wire?

• copper

• glass

• plastic

• rubber

Answer explanation

Copper is the best material for connecting wires due to its excellent electrical conductivity. Glass, plastic, and rubber are insulators and do not conduct electricity, making them unsuitable for this purpose.

Tags

NGSS.MS-PS2-3

NGSS.MS-ETS1-1

Why would the Declaration of Independence be stored surrounded by a Group 18 element?

• A) They are good conductors of heat.

• B) They are chemically inert in nature.

• C) They have more reactive nuclei than metals.

• D) They have different numbers of valence electrons.

Answer explanation

The Declaration of Independence would be stored surrounded by a Group 18 element because they are chemically inert in nature. This inertness helps protect the document from reactions that could cause damage.

A student develops a model that highlights elements that have the most similar properties. Which model is accurate?

• A

• B

• C

• D

Answer explanation

Model A accurately highlights elements with similar properties, making it the correct choice. It effectively groups items based on shared characteristics, which aligns with the student's goal.

Tags

NGSS.MS-PS1-1

An element with which property will be classified as a metal?

• brittle

• ductile

• dull

• inert

Answer explanation

An element classified as a metal is typically ductile, meaning it can be stretched into wires without breaking. In contrast, brittle elements break easily, dull elements lack luster, and inert elements do not react chemically.

What is a chemical property of Kr?

• It is highly reactive.

• It is inert.

• It will form an ionic bond with Cl.

• It is a good conductor of electricity.

Answer explanation

Krypton (Kr) is a noble gas, known for its lack of reactivity. This inertness means it does not readily form bonds with other elements, making 'It is inert' the correct choice.

Which element is brittle when a solid and is a poor conductor of electricity and heat?

• calcium

• copper

• sodium

• sulfur

Answer explanation

Sulfur is brittle in its solid form and does not conduct electricity or heat well, unlike metals such as calcium and copper, which are malleable and good conductors.