Stemscopes Exam Chemistry Fundamentals 3

Question 1

Which of the following is a pure substance?

Accepted Answer

Gold

Answer

Salt water

Answer

Air

Answer

Soil

Question 2

What is the term for the energy needed to start a chemical reaction?

Accepted Answer

Activation energy

Answer

Potential energy

Answer

Kinetic energy

Answer

Thermal energy

Question 3

Elements in the same group (column) of the periodic table share which property?

Accepted Answer

Same number of valence electrons

Answer

Same atomic mass

Answer

Same number of neutrons

Answer

Same atomic number

Question 4

What type of reaction produces a precipitate?

Accepted Answer

Double displacement reaction

Answer

Synthesis reaction

Answer

Combustion reaction

Answer

Decomposition reaction

Question 5

Acids have a pH:

Accepted Answer

Less than 7

Answer

Greater than 7

Answer

Equal to 7

Answer

Equal to 14

Question 6

What is an isotope?

Accepted Answer

An atom with a different number of neutrons

Answer

An atom with a different number of protons

Answer

An atom with a different number of electrons

Answer

A different element with the same mass