Question

1. classify each underlined word as an element, compound, homogeneous mixture, or heterogeneous mixture. learning target 7 a. we exhale co₂ during breathing. b. chicken noodle soup is good when you feel sick. c. potting soil is used to grow plant seedlings. d. many people use saline (salt) solution to store contact lenses e. sodium chloride (nacl) is known commonly as table salt f. an ice cube made from tap water on a hot day is refreshing. g. bronze is an alloy made of copper and tin. h. chalk (caco₃) is used to write on a board i. fresh squeezed oj for breakfast j. an iron nail used to make a deck

Explanation:

Step1: Recall definitions

Elements are pure substances made of one - type of atom. Compounds are pure substances made of two or more different types of atoms chemically combined. Homogeneous mixtures have uniform composition throughout, and heterogeneous mixtures have non - uniform composition.

Step2: Analyze a

$\ce{CO2}$ is a compound as it is made of carbon and oxygen atoms chemically bonded.

Step3: Analyze b

Chicken noodle soup is a heterogeneous mixture as it has visible different components like noodles, chicken pieces etc.

Step4: Analyze c

Potting soil is a heterogeneous mixture as it contains different components like sand, clay, organic matter etc. that are not uniformly distributed.

Step5: Analyze d

Saline (salt) solution is a homogeneous mixture as salt is uniformly dissolved in water.

Step6: Analyze e

Sodium chloride ($\ce{NaCl}$) is a compound as it is made of sodium and chlorine atoms chemically combined.

Step7: Analyze f

An ice cube made from tap water is a compound (water is $\ce{H2O}$) but tap water may also contain some dissolved substances making it a homogeneous mixture at a very low level of impurity. Considering water as the main component, we can say it is a compound.

Step8: Analyze g

Bronze is a homogeneous mixture (alloy) as the copper and tin atoms are uniformly mixed at the atomic level.

Step9: Analyze h

Chalk ($\ce{CaCO3}$) is a compound as it is made of calcium, carbon and oxygen atoms chemically bonded.

Step10: Analyze i

Fresh squeezed OJ (orange juice) is a heterogeneous mixture as it may contain pulp and other non - uniformly distributed components.

Step11: Analyze j

An iron nail is an element as it is mostly made of iron atoms.

Answer:

a. Compound
b. Heterogeneous mixture
c. Heterogeneous mixture
d. Homogeneous mixture
e. Compound
f. Compound
g. Homogeneous mixture
h. Compound
i. Heterogeneous mixture
j. Element