Science 14 Review

Why might a useful chemical also be dangerous?

• It can be harmful to breathe in

• It isn't. If it is useful, then it can't be dangerous

• It is expensive.

• It is difficult to store.

Give examples of hazardous chemicals often found in the home.

• Water and salt

• Vinegar and baking soda

• Bleach and ammonia

• Sugar and flour

Match the WHMIS symbols with their description

• Oxidizing

• 
• Toxic

• 
• Harmful

• 
• Flammable

• 
• Health Hazard

• 

Which of the following is NOT part of the particle theory of matter?

• Particles are not moving.

• Matter is made of small particles.

• All particles in pure substances are the same

• There are spaces between particles; the amount of space varies depending on the state of matter

• The particles in a substance are attracted to one another

Identify where to find metals, non-metals, and metalloids on the periodic table.

• Metals are on the right, non-metals on the left, metalloids in the middle.

• Metals are on the left, non-metals on the right, metalloids in between.

• Metals are in the middle, non-metals on the right, metalloids on the left.

• Metals are on the right, non-metals in the middle, metalloids on the left.

Each property describes a metal or non metal element. Sort them.

​

Groups:

(a) Non-metals

,

(b) Metals

• Greenish-yellow gas

• Grayish solid that is shiny when sanded

• Silver-coloured solid that conducts electricity

• Very shiny silver-coloured liquid that conducts electricity

• Very brittle brown crystal

What is the difference between an element and a compound?

• An element is a pure substance, while a compound is a mixture.

• An element is made of one type of atom, while a compound is made of two or more types of atoms.

• An element can be broken down into simpler substances, while a compound cannot.

• An element is always a solid, while a compound is always a liquid.

How can a decomposition reaction help you determine whether a pure substance is an element or a compound?

• It shows if the substance can be broken down into simpler substances.

• It changes the color of the substance.

• It makes the substance dissolve in water.

• It increases the temperature of the substance.

What does the 2 tell us?

• The amount of hydrogen in the compound.

• That there are two molecules.

• The amount of oxygen in the compound.

• The atomic number of the element.

Write the chemical formula for a compound that is made up of one atom of nitrogen and two atoms of oxygen.

• NO₂

• N₂O

• NO

• N₂O₃