Question

elements, molecules, compounds, mixtures
classify each of the materials below. in the center column, state whether the material is a pure substance or a mixture. if the material is a pure substance, further classify it as either an element, molecule, and/or compound in the right column. similarly, if the material is a mixture, further classify it as homogenous or heterogenous in the right column.
material pure substance or mixture element / molecule / compound homogenous / heterogenous
sugar + pure water (c₁₂h₂₂o₁₁ + h₂o)
iron filings (fe)
limestone (caco₃)
orange juice (no pulp)
pacific ocean
air inside a balloon
aluminum (al)
bromine (br₂)
acetylene (c₂h₂)
tap water in a glass
soil
pure water (h₂o)
chromium (cr)
chex mix
salt + pure water (nacl + h₂o)
benzene (c₆h₆)
muddy water
brass (cu mixed with zn)

Explanation:

Step1: Recall definitions

A pure substance is either an element or a compound. An element consists of only one - type of atom, a compound consists of two or more different types of atoms chemically bonded. A mixture is a combination of two or more substances that are not chemically combined. A homogeneous mixture has a uniform composition throughout, while a heterogeneous mixture has a non - uniform composition.

Step2: Analyze Sugar + Pure Water

It is a mixture. Sugar dissolves in water to form a homogeneous mixture.
- Pure Substance or Mixture: Mixture
- Element / Molecule / Compound Homogenous / Heterogenous: Homogenous

Step3: Analyze Iron Filings (Fe)

It is a pure substance and an element.
- Pure Substance or Mixture: Pure Substance
- Element / Molecule / Compound Homogenous / Heterogenous: Element

Step4: Analyze Limestone ($CaCO_3$)

It is a pure substance and a compound.
- Pure Substance or Mixture: Pure Substance
- Element / Molecule / Compound Homogenous / Heterogenous: Compound

Step5: Analyze Orange Juice (no pulp)

It is a mixture and homogeneous.
- Pure Substance or Mixture: Mixture
- Element / Molecule / Compound Homogenous / Heterogenous: Homogenous

Step6: Analyze Pacific Ocean

It is a mixture and heterogeneous (due to presence of salts, sand, organisms etc. in non - uniform distribution).
- Pure Substance or Mixture: Mixture
- Element / Molecule / Compound Homogenous / Heterogenous: Heterogenous

Step7: Analyze Air inside a balloon

It is a mixture and homogeneous (a well - mixed combination of gases).
- Pure Substance or Mixture: Mixture
- Element / Molecule / Compound Homogenous / Heterogenous: Homogenous

Step8: Analyze Aluminum (Al)

It is a pure substance and an element.
- Pure Substance or Mixture: Pure Substance
- Element / Molecule / Compound Homogenous / Heterogenous: Element

Step9: Analyze Bromine ($Br_2$)

It is a pure substance and a molecule (a diatomic molecule of the same element).
- Pure Substance or Mixture: Pure Substance
- Element / Molecule / Compound Homogenous / Heterogenous: Molecule

Step10: Analyze Acetylene ($C_2H_2$)

It is a pure substance and a compound.
- Pure Substance or Mixture: Pure Substance
- Element / Molecule / Compound Homogenous / Heterogenous: Compound

Step11: Analyze Tap water in a glass

It is a mixture and homogeneous (contains dissolved minerals etc. uniformly).
- Pure Substance or Mixture: Mixture
- Element / Molecule / Compound Homogenous / Heterogenous: Homogenous

Step12: Analyze Soil

It is a mixture and heterogeneous (contains different particles like sand, clay, organic matter etc. non - uniformly).
- Pure Substance or Mixture: Mixture
- Element / Molecule / Compound Homogenous / Heterogenous: Heterogenous

Step13: Analyze Pure Water ($H_2O$)

It is a pure substance and a compound.
- Pure Substance or Mixture: Pure Substance
- Element / Molecule / Compound Homogenous / Heterogenous: Compound

Step14: Analyze Chromium (Cr)

It is a pure substance and an element.
- Pure Substance or Mixture: Pure Substance
- Element / Molecule / Compound Homogenous / Heterogenous: Element

Step15: Analyze Chex Mix

It is a mixture and heterogeneous (contains different types of snacks non - uniformly).
- Pure Substance or Mixture: Mixture
- Element / Molecule / Compound Homogenous / Heterogenous: Heterogenous

Step16: Analyze Salt + Pure Water ($NaCl + H_2O$)

It is a mixture and homogeneous.
- Pure Substance or Mixture: Mixture
- Element / Molecule / Compound Homogenous / Heterogenous: Homogenous

Step17: Analyze Benzene ($C_6H_6$)

It is a pure substance and a compound.
- Pure Substance or Mixture: Pure Substance
- Element / Molecule / Compound Homogenous / Heterogenous: Compound

Step18: Analyze Muddy Water

It is a mixture and heterogeneous (mud particles are not uniformly distributed).
- Pure Substance or Mixture: Mixture
- Element / Molecule / Compound Homogenous / Heterogenous: Heterogenous

Step19: Analyze Brass (Cu mixed with Zn)

It is a mixture and homogeneous (an alloy is a homogeneous mixture of metals).
- Pure Substance or Mixture: Mixture
- Element / Molecule / Compound Homogenous / Heterogenous: Homogenous

Answer:

Material	Pure Substance or Mixture	Element / Molecule / Compound Homogenous / Heterogenous
Iron Filings (Fe)	Pure Substance	Element
Limestone ($CaCO_3$)	Pure Substance	Compound
Orange Juice (no pulp)	Mixture	Homogenous
Pacific Ocean	Mixture	Heterogenous
Air inside a balloon	Mixture	Homogenous
Aluminum (Al)	Pure Substance	Element
Bromine ($Br_2$)	Pure Substance	Molecule
Acetylene ($C_2H_2$)	Pure Substance	Compound
Tap water in a glass	Mixture	Homogenous
Soil	Mixture	Heterogenous
Pure Water ($H_2O$)	Pure Substance	Compound
Chromium (Cr)	Pure Substance	Element
Chex Mix	Mixture	Heterogenous
Salt + Pure Water ($NaCl + H_2O$)	Mixture	Homogenous
Benzene ($C_6H_6$)	Pure Substance	Compound
Muddy Water	Mixture	Heterogenous
Brass (Cu mixed with Zn)	Mixture	Homogenous