Chemical Reactions FA#1

These are particles that are too small to see and all matter is made up of these. What are they?

• compounds

• atoms

• melting point

• boiling point

Answer explanation

atoms also contain a nucleus with protons and neutrons, along with an electron cloud

There are 118 of these represented on the periodic table. They are made up of atoms and are in the purest form.

• element

• compound

• molecule

• melting point

Answer explanation

elements are made up of atoms!

What type of charge does a proton have?

• neutral

• positive

• negative

• model

Answer explanation

the proton is also the same as the atomic number on the periodic table!

In chemistry, what is a substance?

Answer explanation

is any matter made of the same atom or group of atoms that repeats over and over to form the entire sample of matter. Iron, water, salt are all examples of substances

In chemistry, what would be considered a property of a substance?

Answer explanation

Properties are observable qualities of a substance such as its color (color change), odor, and boiling point.

What is a chemical property?

Answer explanation

Chemical properties are properties that can only be observed when substances undergo chemical reactions (gas bubbles or color changes for example

What is a physical property?

Answer explanation

Physical properties are properties that can be observed without substances undergoing chemical reactions (such as a color or a phase change).

Two substances are going through a chemical reaction, but you are unsure if the reaction is endothermic or exothermic. What could you do to test this out?

Answer explanation

You could feel the beaker--if it is cold, that would mean it is endothermic and if it is hot, that would mean it is exothermic or take the temperature of the reaction in solution.

Look at the two samples in the picture. Are these samples made up of the same type of substance? Explain why or why not.

Answer explanation

It is hard to tell from the picture. You would need to know the chemical properties of the substances to know what the substance is made up of.

Two samples are being observed and analyzed in a lab. Read the description of each.

Sample #2 This substance has a weird color to it.

Sample #3 This substance is light grey, with an appearance of fine, grained crystals.

Explain which sample has a more scientific description and why.

Answer explanation

Sample #3 since it is more descriptive (the color and size of the grains are identified as opposed to the simple and unclear description for sample #2)