2017 7th Grade 2nd Semester Exam Review

In an atom, the number of protons equals the number of ______________

• nuclei
• electrons
• neutrons
• isotopes

Substances that cannot be broken down chemically into other substances are _________________.

• elements
• compounds
• mixtures
• solutions

Electrons have what type of charge?

• Positive
• Negative
• Neutral

On the periodic table, what tells you the  number of protons in an atom for the different elements?

• the position of the element in it is column
• the element's chemical symbol
• the element's atomic number
• the element's atomic mass

The elements in a row of the periodic table

• are in the same family
• have teh same or nearly the same properties
• have the same average atomic mass
• have properties that change in a pattern

From an element's location in the periodic table, you can predict

• its properties
• its chemical name
• its chemical symbol
• when it was discovered

What is the only for sure sign that a chemical reaction occured?

• a change in the state of matter 
• create a new substance
• change volume
• create energy

Which one of the following is a physical change?

• the solution was heated for 2 minutes until it boiled
• a solid formed when two liquids were mixed together
• two solutions were mixed and the resulting solution felt hot
• the color of two mixed solutions changed from clear to white

Which of the following activities results in a chemical change?

• a piece of metal is cut in half.
• an ice cube melts
• roasting a marshmallow over a burning fire
• mixing together flour and sugar

Which of the following is an element?

• H₂O
• NaCl
• N₂
• C₆H₁₂O₆