Question Bank for Grade 8 Science

Which statement best explains how periods on the periodic table are organized?

• increasing atomic number from left to right
• increasing number of neutrons from left to right
• decreasing number of electrons from left to right
• decreasing atomic mass number from left to right

Where are the most reactive metals located on the periodic table?

• the uppermost complete row of the table
• the rows at the bottom of the table connecting two section
• the column at the far left side of the table
• the second column from the right side of the table

Which elements are most likely to react in the same manner in a chemical reaction?

• elements in the same group
• elements in the same period
• elements with similar atomic masses

If an element has no electrons to share and is stable, what family is it found in?

• alkali metals
• noble gases
• halogens

Which property is unique for each element?

• mass number
• atomic number
• state of matter

What coefficient for O₂ demonstrates the law of conservation of mass?
CH₄(g) + __O₂(g) → CO₂(g) + 2H₂O(g)

• 1
• 2
• 3
• 4

Which is best represented by the equation?
2Mg + O₂ → 2MgO

• Law of Conservation of Energy
• Law of Conservation of Mass
• Law of Superposition

What is the importance of a closed container in a chemical reaction?

• to observe the mass before and after the reaction occurs
• to keep any materials from interfering with the reaction
• to observe the loss of mass after the reaction occurs

Which is a physical change?

• burning match 
• vinegar in baking soda 
• melting butter
• cooking an egg

What is an example of a Chemical change?

• Ripped paper 
• boiled egg
• cracked egg
• sugar in water