2.2 What are some ways to describe matter? Concept 1: Matter can be described by its physical properties Name:__________________________ Date:___________________________

What are some ways to describe matter? Matter is anything that has mass and takes up volume. Matter has different properties: Physical properties Chemical properties Physical property: Characteristic of matter that can be observed or measured without changing its chemical identity The observations made can be quantitative or qualitative. Quantitative observations include a number and a unit Qualitative observations are descriptions of the object. Pick an object in the classroom. Can you think of some quantitative and qualitative observations?

Physical Properties: Qualitative Observations Take a look at the bottom diagram to the right. Write down some qualitative observations on this slide

Choose an object in this classroom to describe Without writing down the name of the object, write down as many properties as you can about it here: Trade descriptions with a partner. Can you figure out the identity of their object? My partner’s object: __________________________ Properties that helped make the object more or less difficult to identify:

Physical Properties: Quantitative Observations Matter can be described using the terms mass, volume and density Mass is the amount of matter that an object contains. Measured in the units of grams (g), milligrams (mg), kilograms (kg) Volume is the amount of space that an object takes up. Gas and liquids are usually measured in litres (L) and milliliters (mL). solids are measured in the base units of metres cubed (m3)

Physical Properties: Quantitative Observations Density: Amount of matter in a given volume. For solids we can use g/cm3 For liquids and gases we can use g/mL Which one is more dense? Circle it. Why?

Physical Properties: Quick Check 1. What is the difference between a quantitative physical property and a qualitative physical property?   2. Identify each of the physical properties as qualitative or quantitative. Physical Property Quantitative or Qualitative? Butter is a solid at room temperature. Glass is rated 5.5 on Mohs Hardness Scale. The density of cooking oil is 0.93g/cm3 Silver is a lustrous (shiny) metal. Oxygen is a colourless gas. The freezing point of water is 0°C. Water is a solid (ice) at its freezing point.

Comparing Density Italian salad dressing is made of three main components, water, oil and solid flavouring. Think about what happens to this dressing when it settles. What are the “three layers” it separates into? Position in Container DENSITY SEPARATE LAYERS Top Least Dense Middle Less Dense Bottom Most Dense Oil Water Solid Flavouring

Comparing Density LOWER density objects will float on TOP of HIGHER density objects. When looking at oil and water, there are other factors that cause them to separate.

Calculating Density m D V Two factors that affect density are mass and volume. m D V

Calculating Density Volume of a liquid can be measured in mL. Example: Orange juice is tested to ensure it meets certain standards. One standard is density. If a sample of orange juice has a mass of 312 g and a volume of 250 mL, what is its density? Calculate with students using white board Density = 1.25g/mL

Calculating Density Honey is more dense than water with a density of 1.42 g/mL. If a jar contains 213 g of honey, what is the volume of honey in the jar? Volume = 150mL

Calculating Density Volume of a solid can be measured in cm3 Example: What is the density of a 250 g rectangular box that is 10 cm long, 5 cm wide and 2 cm in height? Density: 2.5 g/cm3

Calculating Density Example: The density of salt is 2.16g/cm3. What is the mass if you have a cube of salt with a volume of 400 cm3? Mass = 846 g

What do we do if we have an irregular shaped object? Use displacement: the amount of space that an object takes up when placed in a fluid Ex. When you add ice to your beverage Final volume – Initial volume = displacement The amount of displacement is the volume of the solid object Liquids can be measured using a graduated cylinder

Calculating density using displacement Example: A rock is dropped into a full can of water and causes 35 mL of water to spill out. The mass of the rock is 260 g. Calculate the density of the rock. Density = 7.43 g/mL