Chemistry Flashcards

Questions and Answers

If a solid contains some particles that melt at 50°C and other particles that melt at 110°C, what must be true about the solid?

The solid is a mixture.

Which of the following definitions characterizes an element?

Contains only one type of atom (correct)

Contains multiple types of atoms

Can be broken down into simpler substances

Is always a solid

Which of the following is true about pure substances?

They have varying chemical properties

Have the same chemical properties throughout (correct)

Contain multiple elements

They can be mixtures

A liquid boils at 120°C until it all evaporates, leaving an empty container. What is most likely true about the liquid?

The liquid was a pure substance. Signup and view all the answers

What defines a mixture?

It can be broken down into its basic substances through physical means. Signup and view all the answers

Jayla has two wires that are both made of pure copper. One of the wires is bigger than the other wire. Which of the following is true about the particles of the wires?

The particles in both of the copper wires will be exactly the same. Signup and view all the answers

How many elements are found in the following chemical equation?

2 Signup and view all the answers

One of the element carbon combines with one of the element oxygen to form one of the compound carbon dioxide.

atom; molecule; molecule Signup and view all the answers

Which of the following is true about a compound and its elements?

The properties of a compound are different than the properties of its elements Signup and view all the answers

Vince is baking a cake. He pours flour and sugar into an empty bowl. The substance in the bowl is a(n) __________.

mixture Signup and view all the answers

What is the smallest particle of an element?

atom Signup and view all the answers

Which is a substance made up of only one kind of atom?

Element Signup and view all the answers

Sharon pours salt into a glass of water. The salt dissolves. The substance in the glass is a(n) __________.

mixture Signup and view all the answers

The chemical formula of a particular substance is NO2. Which of the following is a correct description of the substance?

A compound made up of 1 nitrogen atom and 2 oxygen atoms. Signup and view all the answers

Which of the following molecular models represents an element?

Yellow Signup and view all the answers

Marcus has a piece of metal. He knows that the metal is either made of pure zinc or a mixture of zinc and iron. What property could he easily measure in the lab to help him determine whether the metal is pure zinc?

Density Signup and view all the answers

The air we breathe contains different individual gases (mostly nitrogen and oxygen). Which of the following correctly describes the air we breathe?

Mixture Signup and view all the answers

Lemonade is best described as _______.

a mixture Signup and view all the answers

Harley mixes a cup of sugar and a cup of salt together inside a large bowl. The sugar and salt form a mixture and do not chemically combine. Which of the following conclusions can be made about these particles?

All of these Signup and view all the answers

Study Notes

Mixtures and Pure Substances

A solid that melts at different temperatures (e.g., 50°C and 110°C) is classified as a mixture.
A mixture can be separated into its basic substances using physical methods.
When flour and sugar are combined in a bowl, they form a mixture rather than a chemical compound.
Salt dissolved in water creates a mixture, demonstrating that substances can retain their properties when mixed without chemical reactions.

Elements and Compounds

An element consists of only one type of atom.
Pure substances display consistent chemical properties throughout.
The properties of a compound differ from those of its constituent elements; for example, carbon dioxide has characteristics distinct from those of carbon and oxygen.
The smallest unit of an element is called an atom, while the smallest unit of a compound is a molecule.
The chemical formula NO2 indicates a compound consisting of one nitrogen atom and two oxygen atoms.

Other Relevant Concepts

The air we breathe, primarily composed of nitrogen and oxygen, is categorized as a mixture due to the presence of various individual gases.
Density is a measurable property that can help identify if a metal (like zinc) is pure or a mixture.
In molecular models, elements can be distinguished, such as a yellow model representing a specific element.

Key Facts

A pure substance remains consistent in chemical properties, unlike mixtures.
Compound formation involves combining elements, leading to a new substance with unique properties.
Everyday examples, such as lemonade, exemplify mixtures as they combine multiple ingredients without forming a new chemical entity.

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Description

Test your knowledge of key chemistry concepts with these flashcards. From the characteristics of solids, elements, and pure substances, this quiz will help reinforce your understanding of fundamental principles in chemistry.