Units used to measure the density of solids and liquids.
Density of a Liquid = grams per milliliters (g/mL).
100
Explain the difference between chemical and physical changes.
Chemical changes: Two substances combine to create a new substance with different properties.
Physical changes: Two substances are combined and each retains the same properties as the elements that make it up.
100
Define element
Element: a pure substance that is composed of only one type of atom. It cannot be broken down into simpler substances.
100
What is a solution.
A solution is a homogeneous mixture of a solvent and a solute. The solute is the substance that is dissolved and the solvent is the substance that the solute is dissolved into. For example in a solution of salt water the salt is the solute and the water is the solvent.
100
What happens when you place an object with a density of 2.5g/cm3 into water that has a density of 1.0g/mL? Explain why your answer would happen.
The object would sink because it has a higher density than the water.
200
List the different tools that can be used to measure the Volume of a liquid
Volume of a liquid: graduated cylinder, beaker, measuring cup/spoon
200
List four different evidences of a chemical change.
Change in color, odor, the release of energy or heat, light, sounds, and bubbling or fizzing.
200
Compounds can only be broke down by a chemical change. List two specific ways to break down compounds.
Adding heat or electrolysis (separating by electrical shock)
200
Compare and contrast heterogeneous and homogenous mixtures.
Homogenous mixtures are the same throughout. You can take a sample from any part of the mixture and it will have the same composition. Heterogeneous mixtures are different throughout. They may have clumps or large concentrations of different elements throughout a sample. They are similar because they are both mixtures and are made of one or more substance that is physically combined.
200
List 3 physical changes.
Melting, mixing, separating, crushing, tearing, solid to liquid, liquid to gas, evaporating, dissolving, , grinding, and sanding.
300
What happens when you put liquids (that don’t mix) of different densities into a graduated cylinder?
The liquids with the highest densities would sink to the bottom to form layers. The layer on the top would be the liquid with the lowest density.
300
List four physical properties of matter.
physical properties of matter: color, shape, size, state, melting point, freezing point, boiling point, malleability (the ability to bend), density, volume, mass, or solubility (the ability to dissolve)
300
Elements join to form compounds in a specific ______________.
mass ratio
300
True of False: Salt water is a homogeneous mixture
True
300
Write a chemical formula that represents a compound and one that represents an element.
Element: only one capital letter! C, H, Cl, Mg4, F8.
Compound: two or more capital letters! C6H12O6, H2O, CO2, H2O2.
400
Is density and Intensive or Extensive property of matter?
Intensive (It does not depend on the amount)
400
Changes of state are considered which type of change? Explain why.
Changes of state are PHYSICAL changes because the substance still has the same chemical properties, just in a different form. Water is still water (H2O) when it is a liquid, solid (ice), or gas (water vapor).
400
How is a compound different from a mixture?
Mixtures DO NOT combine in a specific ratio, they are physically combined and can be separated, the elements in the mixture keep their physical properties, and they do not form a new substance.
400
Solubility is a substances ability to dissolve. List three things that can make a substance more soluble.
crushing it into smaller pieces, adding heat, stirring or shaking quickly
400
Jack has a rock. The rock has a mass of 6g and a volume of 3cm3. What is the density of the rock?
D = m/v so the density of the rock equals 6/3. Density = 2 g/cm3.
500
Is Density a physical or a chemical property?
Physical Property
500
Why are chemical properties harder to observe than physical properties?
Chemical properties change the substances identity or makeup.
500
Why are compounds considered to be a pure substance?
It is a pure substance because compounds are composed of only one type of particle and the particles are chemically combined. Also different samples of any compound have the same elements in the same proportion. For example water is always composed of 2 hydrogen molecules and 1 oxygen molecule.
500
List 2 ways that mixtures can be separated.
filtering, settling, and evaporation
500
True or False: The total mass of reactants is ussually greater than the total mass of products
FALSE
The total mass of the reactants equals the total mass of the products.