Basics of Chemistry # 4Versión en línea Put yourself in the situation by reading the scenario and answering the questions. por Rosalind Carter 1 Chloe has come to the Crystal Salon & Spa to see her favorite stylist, Jayden, about updating her look. In addition to shortening her long hair a bit, Chloe would like to change the color from dark brown to a light brown. While washing his hands before the client consultation with Chloe, Jayden dripped some water onto the countertop. When he came back later to wipe it up, it had evaporated. What happened to the drops of water? a The water underwent a chemical change. b The water underwent a physical change. c The water became a pure substance. d The water became an organic substance 2 Chloe has come to the Crystal Salon & Spa to see her favorite stylist, Jayden, about updating her look. In addition to shortening her long hair a bit, Chloe would like to change the color from dark brown to a light brown. Chloe wants to lighten the color of her dark hair, which will require the use of both haircolor and hydrogen peroxide. Hydrogen peroxide (H2O2) is an example of a(n): a compound molecule. b elemental molecule. c miscible liquid. d immiscible liquid. 3 Chloe has come to the Crystal Salon & Spa to see her favorite stylist, Jayden, about updating her look. In addition to shortening her long hair a bit, Chloe would like to change the color from dark brown to a light brown. When Jayden applies the hydrogen peroxide to Chloe's dark hair, the melanin pigments in her hair will be: a ionized. b neutralized. c oxidized. d emulsified. 4 Chloe has come to the Crystal Salon & Spa to see her favorite stylist, Jayden, about updating her look. In addition to shortening her long hair a bit, Chloe would like to change the color from dark brown to a light brown. As the hydrogen peroxide is absorbed, Chloe's hair slowly begins to lighten. What is happening to the melanin in Chloe's hair? a It is being changed from hydrophilic to lipophilic. b It is being changed from lipophilic to hydrophilic. c It is undergoing a physical change. d It is undergoing a chemical change. 5 Tayla is a cosmetology student who wants to develop a better understanding about the basics of chemistry so that she will be able to use professional products more effectively and safely. To help practice what she's learned, Tayla is examining and experimenting with some beauty products and implements in her home. Tayla examines her makeup brush and begins to list its properties. Which of these is a chemical property of Tayla's makeup brush? a The wooden handle is flammable. b The synthetic bristles will melt at a high temperature. c The bristles are black. d The brush is a solid, not a liquid or gas. 6 Tayla is a cosmetology student who wants to develop a better understanding about the basics of chemistry so that she will be able to use professional products more effectively and safely. To help practice what she's learned, Tayla is examining and experimenting with some beauty products and implements in her home. Tayla selects a variety of items and places them on the table. Which of her selected items is an organic substance? a scissors made of steel b hydroxide hair relaxer c glass of pure water d plastic comb 7 Tayla is a cosmetology student who wants to develop a better understanding about the basics of chemistry so that she will be able to use professional products more effectively and safely. To help practice what she's learned, Tayla is examining and experimenting with some beauty products and implements in her home. Tayla keeps the beauty products that she uses regularly on the dresser in her bedroom. Which of these products that Tayla often uses is an example of a suspension? a hand lotion b nail polish c nail primer d cold cream 8 Tayla is a cosmetology student who wants to develop a better understanding about the basics of chemistry so that she will be able to use professional products more effectively and safely. To help practice what she's learned, Tayla is examining and experimenting with some beauty products and implements in her home. Tayla knows from her studies that ammonia is used in hair products to raise their pH so they can penetrate the hair shaft, but that it has a strong odor. Which type of ingredient is often used in place of ammonia to raise the pH of hair products? a silicones b volatile alcohols c glycerin d alkanolamines Feedback 1 The water underwent a physical change from liquid to vapor. 2 A compound molecule is a chemical combination of two or more at-oms in definite proportions. Hydrogen peroxide is made up of two hydrogen atoms and two oxygen atoms. 3 The hydrogen peroxide acts as an oxidizing agent, releasing oxygen into the melanin pigment in the hair. 4 When hydrogen peroxide is applied to the melanin in hair, it oxidizes, and oxidation is a type of chemical change. 5 Chemical properties are characteristics that can only be determined by a chemical reaction and a chemical change in the substance. 6 Plastic is considered an organic substance because it contains car-bon. 7 Nail polish is an example of a suspension, which is an unstable physical mixture of undissolved particles in a liquid. 8 Alkanolamines are alkaline substances used to neutralize acids or raise the pH of many hair products, and are often used in place of ammonia be-cause they produce less odor.
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