Substance vs Mixture Remediation

Substances vs. Mixtures REMEDIATION

Unit Standards & Learning Goals

• SC.8.P.8.5: Recognize that there are a finite number of elements and that their atoms combine in a multitude of ways to produce compounds that make up all of the living and nonliving things that we encounter.

  • Understand that atoms can join together to form compounds

  • Know that combinations of atoms make up all living and nonliving things 

• SC.8.P.8.9: Distinguish among mixtures (including solutions) and pure substances

  • Identify or sort pure substances (elements & compounds) and mixtures using pictures, chemical formulas, and/or descriptions

  • Explain the differences between pure substances and mixtures

• SC.8.P.8.8: Identify basic examples of and compare and classify the properties of compounds, including acids, bases, and salts

  • Identify basic examples of acids, bases, and neutral substances

  • Compare and contrast properties of acids, bases, and salts (neutral)

Pure Substances

• One type of matter

• Elements (like Hydrogen or Oxygen) or Compounds (like water H₂O)

• Cannot be separated physically (You cannot pull apart the hydrogen and oxygen in the compound water-H₂O with your hands)

• Composition is definite (no question about it) and constant (always the same). For example water is definitely always H₂O

• A model of a pure substance will look like a repeating pattern of the same substance

Elements

• one type of atom

• individual atoms or are chemically combined

• Chemical formula has ONE capital letter

​Helium (He)

​Oxygen (O₂)

​Notice every particle is the same---two yellow. This makes it a pure substance. What makes it an element is that the two atoms in the particle are the same.

Elements combine in many ways to form compounds that make up all the substances we encounter

Examples show different ways that hydrogen and oxygen can combine to make different substances

​Compounds

• 2 or more different elements chemically combined

• Chemical formula has 2 or more capital letters

• Fixed ratio of atoms (water is always 2 hydrogen atoms and 1 oxygen atom-H₂O)

• Compound has different properties from its elements

​Notice every particle is the same---one red and one yellow. This makes it a pure substance. What makes it a compound is that the two atoms in the particle are different.

Categorize

Options (18)

one type of atom

multiple types of atoms chemically bonded in a constant ratio

Hydrogen (H₂)

Oxygen (O₂)

Neon (Ne)

Water (H₂O)

Carbon (C)

Nitrogen (N)

Carbon Dioxide (CO₂)

Glucose (C₆H₁₂O₆)

Ammonia (NH₃)

Table Salt (NaCl)

Sort the following pure substances as an element or compound.

Element

Compound

​Mixtures

• 2 or more pure substances ​physically combined

• Can have different amounts of each substance (For example, you can add more sugar to make tea sweeter)

• Each substance keeps its own properties

• NOT pure because there's more than one type that do not chemically bond all together-they stay separate

​Another type of substance

​One type of substance

​

Categorize

Options (13)

Elements or compounds

solutions-one substance dissolved into another

one type of substance (may be chemically combined)

two or more types of substances physically combined

constant composition

variable composition

chemically combined

physically combined

Organize these options into the right categories

Pure Substance

Mixture

Multiple Choice

This picture of a compound is a pure substance because...?

• It has the same substance throughout (homogeneous)

• It has different types of atoms throughout

• It has different substances throughout (heterogeneous)

​Types of mixtures

​Homogeneous
(Solutions)

​Heterogeneous

• Solution: one substance is dissolved into another

• looks the same once mixed (uniform throughout)

• particles distribute evenly

• visually you can see its components (parts look different from each other)

• particles have clear boundaries between types (clumps)

​Solutions (homogeneous mixtures)

• One substance dissolved into another

• Solute + Solvent = Solution

• Remember the theif "puts the loot in the vent as a solution to not getting caught"

​Inside a glass of lemonade you've dissolved sugar and lemon juice into water

​Heterogeneous mixtures

​Different substances are clearly visible

Categorize

Options (9)

homogeneous mixtures

uniform composition

one substance is dissolved into another

parts are clearly visible (looks different)

not uniform in composition

Organize these options into the right categories

Solutions

Heterogeneous mixtures

​pH scale

​0-6 Acids

8-14 Bases (Alkali)

7 Neutral

• Releases H+ ion when in solution

• tastes sour

• reacts with metals (corrosive)

Acids

• Releases OH- ion when in solution

• ​tastes bitter

• feels slippery

Bases (Alkali)

Neutral

• Releases equal amounts of H+ and OH- ions

• tastes can vary

• salts have crystal structure

Neutralization

• Chemical reaction between an acid and a base that forms a salt and water

Categorize

Options (12)

lemon juice (pH 2)

milk (pH 6)

vinegar (pH 3)

black coffee (pH 5)

seawater (pH 9)

baking soda (pH 8)

milk of magnesia (pH 10)

Liquid drain cleaner (pH 14)

pure water (pH 7)

sugar solution (pH 7)

vegetable oil (pH 7)

human blood (pH 7.4)

Sort the following common household substances as an acid, base, or neutral solution based on their pH.

Acid

Base (Alkali)

Neutral

Match

Match the following properties to acid, base, or salts

• slippery

• tastes sour

• crystal structure

base

acid

salts

• base

• acid

• salts