Unit 1 - Mass and Measurement

1a - Conservation of Mass

The conservation of mass is a fundamental idea in Chemistry, and is one of the underlying principles that allows us to draw the conclusions that we do.


We will be using a style of note-taking called Cornell Notes. It was created a long time ago by a professor at Cornell University.

We, as people, have relatively terrible memories that are difficult to organize and keep track of. This is why we, as people, are fortunate to have methods of keeping track of information we might need later - in this case by taking notes.

Cornell Notes is a system of notes that is specifically designed to help people study and learn effectively, and that's why many of the teachers at HeLa have decided to adopt it. Having an effective system to keep track of information is extremely helpful, especially when it comes to studying and academics.

Taking Cornell Notes Handout.pdf

Introduction to Mass

To start with the content of the course and get some practice with taking notes, we can take a look at mass and how we define it in chemistry.

What is mass? For our sake, it's a measure of the amount of matter contained in an object. Essentially, the mass of an object is determined by how much "stuff" makes up that object.

It's important to make the distinction between mass and weight- mass is not weight.

Introduction to Mass - Part 1

Introduction to Mass - Part 2

History of the Conservation of Mass

On Lavoisier and the Conservation of Mass.pdf

Lab Safety Guidelines

Safety Equipment

Conservation of Mass Activities

We whiteboarded these with groups, but they could be done individually as practice. The task was to create particle-level diagrams for both experiments that show what's going on before and after the experiment that would account for the changes in mass that we see.

Remember, they don't have to be perfectly accurate, as we haven't even talked about what a chemical reaction is yet, it's more important that we account for change in mass, based on our definition of mass.

Summarizing Conservation of Mass

Practice Work

1a WS1 Mass and Change.pdf
1a WS1 KEY.pdf
1a WS2 Conservation of Mass.pdf
1a WS2 Key.pdf

You should know how to:

  • Represent a sample of matter using a particle-level diagram
  • Describe mass as a measure of the amount of matter in an object
  • Explain how mass is different than weight
  • Explain the reason for a change in mass
  • Describe a system as being open or closed based on description or information about change in mass
  • Correctly predict a change in mass given a real situation
  • Give a particle-level description to explain a change in mass or lack thereof

1b - Measurement and Uncertainty

Introducing Measurement, Uncertainty, Units

Measuring Volume and the Meniscus

Practice Work

1b WS1 Reading Scales.pdf
1b WS1 Key.pdf
1b WS2 Measuring Volume and Temperature.pdf

You should know how to:

  • Define volume
  • Read and report a measurement with the correct precision
  • Report a measurement with an appropriate value for uncertainty
  • Accurately read a volume measurement
  • Draw where water level should be on a graduated cylinder based on a reported volume
  • Find the volume of a solid or predict the final water level based on the volume of an object