Chemical Reactions Unit Test A

A physical change...

• Changes the physical properties of an object, but does not create a new substance.

• Creates a new substance and cannot be undone.

A chemical change...

• Changes the physical properties of an object, but does not create a new substance.

• Creates a new substance and cannot be undone.

Which of the following options provides evidence of a CHEMICAL change?

• Wood is burned releasing ash and smoke

• Rocks separate when soil is sifted

• Water turns to ice when you put it in the freezer

• Salt dissolves in water

Which of the following examples provides evidence of a PHYSICAL change?

• Wood is burned and releases ash and smoke

• Iron rusts over time

• When mixed, baking soda and vinegar form gas bubbles

• A piece of paper changes shape when you rip it up

What did Rutherford discover about atoms?

• An atom is always negatively charged.

• An atom is mostly empty space, but has a dense positively charged center(nucleus).

• An atom is always positively charged.

• All particles will pass straight through gold foil with no change in path.

James Chadwick discovered the

• neutron

• proton

• electron

• nucleus

The following is what type of reaction:
PbCl₂ + AgNO₃ → Pb(NO₃)₂ + AgCl

• Synthesis

• Decomposition

• Single Displacement

• Double Displacement

The following is what type of reaction:
NH₃ + HCl  → NH₄Cl

• Synthesis

• Decomposition

• Single Displacement

• Double Displacement

What type of chemical reaction is this?
Al(OH)₃ → Al₂O₃  + H₂O

• Decomposition

• Combustion

• Synthesis

• Single Displacement 

3Ca + 2AlCl₃ --> 3CaCl₂ + 2Al

• Synthesis
• Decomposition
• Single Displacement
• Double Displacement