Alchemy Quiz 06

How many atoms are represented by the chemical formula NaNO₃?

• 2

• 3

• 4

• 5

Answer explanation

The chemical formula 𝑁𝑎𝑁𝑂3 represents a total of five atoms: one sodium (Na), one nitrogen (N), and three oxygen (𝑂3). (The three should be a subscript.)

Tags

NGSS.MS-PS1-1

Refer to the image of an ethylene molecule. What is the chemical formula for this molecule?

• C₂H₄

• H₂C₄

• 4HC₂

• 2CH₄

Answer explanation

Numbers in front of the chemical symbol are coefficients and they indicate the number of molecules. The image shows only one molecule. When writing a formula that includes carbon and hydrogen, carbon is always listed first.

Tags

NGSS.MS-PS1-1

In the diagrams (A-D), lighter color = nitrogen (N) and darker color = oxygen (O). Which diagram shows nitrogen dioxide (NO₂)?

• A

• B

• C

• D

Answer explanation

NO₂ is one molecule that has one N and two O's.

Tags

NGSS.MS-PS1-1

The chemical formula for the compound copper oxide is Cu₂O. What is most likely to be true about the properties of copper oxide in relation to the properties of copper and oxygen?

• Copper oxide has properties very similar to those of oxygen.

• All three substances have similar properties.

• All three substances have different properties.

• Copper oxide has properties very similar to those of copper.

Answer explanation

Compounds do not have the same properties as their component elements. Instead, they have unique properties that are completely different due to chemical reactions that create new substances.

Tags

NGSS.MS-PS1-1

Which combination of elements would you expect to have the most similar properties?

• hydrogen, H, and helium, He

• nitrogen, N, and oxygen, O

• carbon, C, and silicon, Si

• copper, Cu, and zinc, Zn

Answer explanation

Elements that are in the same (vertical) column have the same number of valence electrons and similar chemical properties.

Which of these elements would you expect to have the greatest reactivity?

• boron, B

• carbon, C

• cesium, Cs

• neon, Ne

Answer explanation

Elements at the bottom of Group 1A and the top of Group 7A are the most reactive. Noble gases in Group 8A are nonreactive.

At room temperature, most of the elements in the periodic table are:

• metals

• nonmetals

• liquids

• gases

Answer explanation

There are metals, 22 nonmetals, and 7 metalloids out of the 118 elements on the periodic table. At room temperature, 11 elements are gases, 2 are liquids, and the remaining 105 are solids.

Is indium a metal, a nonmetal, or a metalloid?

• metal

• nonmetal

• metalloid

• depends on the temperature

• there is no way to tell

Answer explanation

Indium is in Group 3A, and can form ionic bonds with nonmetals.

Tags

NGSS.HS-PS1-1

In what phase or state of matter would you find radon at room temperature?

• solid

• liquid

• gas

• plasma

Answer explanation

Radon is a noble gas.

Tags

NGSS.MS-PS1-4

Group 1A elements are called:

• alkaline Earth metals

• alkali metals

• noble gases

• halogens

• transition metals

Answer explanation

You can review the readings we've done in class to find out the special names for groups of elements.