Atoms and Chemical Reactions

A student is trying to identify an unidentified, solid grey material as a metal or a nonmetal. Which question will best help the student classify the material?

• Is the material malleable or ductile?

• Does the material feel hard to the touch?

• Will the material float in water?

• Does the material feel rough or smooth?

What is the difference between the number of electrons in an atom of selenium, Se, and the number of electrons in an atom of aluminum, Al?

Tags

NGSS.MS-PS1-1

A model of a beryllium atom is shown.

What types of particles are found in the cloud surrounding the atom's nucleus?

• Positively charged particles and negatively charged particles

• Negatively charged particles only

• Neutral particles and positively charged particles

• Positively charged particles only

Tags

NGSS.MS-PS1-1

Sodium and lithium have similar chemical properties. What characteristic of these elements explains why they are chemically similar?

• The atoms both have one valence electron

• Their atoms both have more neutrons then protons

• Their atoms have the same number of energy levels

• Their atoms contain equal numbers of protons and electrons

A compound secreted by honeybees to paralyze intruders in their hive is known as 2-heptanone. The formula for this compound is shown.

CH₃C₄H₈COCH₃

How many atoms of each element are in one molecule of 2-heptanone?

• 4 carbon atoms, 11 hydrogen atoms, and 1 oxygen atom

• 7 carbon atoms, 14 hydrogen atoms, and 1 oxygen atom

• 7 carbon atoms, 11 hydrogen atoms, and 8 oxygen atoms

• 6 carbon atoms, 14 hydrogen atoms, and 3 oxygen atoms

Tags

NGSS.MS-PS1-1

The table shows the chemical formulas for four substances. Which substances have the same number of carbon atoms?

• Substances 1 and 2

• Substances 2, 3, and 4

• Substances 2 and 3 only

• Substance 1 and 3

In which of these compounds are there twice as many oxygen atoms as hydrogen atoms?

• H₃PO₄

• H₂SO₄

• HClO₃

• H₂O

Tags

NGSS.MS-PS1-1

Serotonin is a chemical substance that acts as a neurotransmitter. It helps relay messages in the human brain. The formula of one molecule of serotonin is shown below.

C₁₀H₁₂N₂O

How many atoms in all are in a molecule of serotonin?

Tags

NGSS.MS-PS1-1

Which information could a student determine from only the chemical formula of a protein?

• The color of the protein

• The number of molecules in each sequence that make up a protein

• The physical arrangement of atoms in the structure of the protein

• The number of atoms of each element in the protein

Tags

NGSS.MS-PS1-1

For an investigation a student poured a blue solution CuSO₄ into a beaker. The student placed a shiny, silver-colored strip of zinc metal in the solution and observed the changes.

The student inferred that a chemical reaction occurred. What evidence supports this inference?

• A dark solid formed on the zinc metal

• The zinc metal remained silver-colored and shiny

• The CuSO₄ solution turned blue when the zinc metal was added

• None of these

Tags

NGSS.MS-PS1-2