8.P.1 Review

Which of these options represents a compound?

• P4
• O2
• H2O

When chemical W is added to a liquid, the chemical breaks down into substances X, Y, and Z. It is not possible to break down substances X, Y, and Z into simpler substances. What conclusion is supported by this evidence?

• Chemical W is an element.
• Chemical W is a pure substance.
• Substances X, Y, and Z are elements.
• Substances X, Y, and Z are compounds.

Study the flow chart showing the organization of matter. What term is missing as indicated by the question mark in the flow chart?

• Compounds
• Metals
• Molecules
• solutions

How are the elements organized into the periodic table?

• Elements are ordered by atomic weight.
• Elements are ordered by atomic number
• Elements are arranged alphabetically.
• Elements are grouped by color.

What is the significance of a column in the periodic table?

• A column, better known as a group, includes elements with similar properties.
• A column, better known as a period, includes elements with similar properties.
• A column, better known as a group, includes elements with the same number of electrons.
  
• A column, better known as a period, includes elements with the same number of electrons.

This is a diagram of an oxygen atom.

• 0
• 8
• 16
• 24

halogensWhat is identified in the illustration?

• halogens
• metalloids
• noble gases
• transition metals

Which statement about the elements is true?

• Oxygen and sulfur share similar properties.
• Carbon and nitrogen share similar properties.
• Carbon and silicon have the same number of electrons.
• Oxygen and phosphorus have the same number of protons.

Which term represents a physical property of matter?

• density
• flammability
• reactivity
•  toxicity

Which example shows a physical change taking place?

• Heat is given off.
•  The substance melts.
• A new substance is produced.
• A precipitate is formed.