Gr 8 Natural Sciences Ch 2.1: Pure substances
63 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is true about the properties of elements in a compound?

  • The properties are the same as the individual elements
  • The properties are different from the individual elements (correct)
  • The properties are only slightly different from the individual elements
  • The properties are similar to the individual elements, but with a slight change

    • Which type of molecule is composed of different kinds of atoms?

  • O2 (oxygen)
  • N2 (nitrogen)
  • H2O (water) (correct)
  • CO (carbon monoxide)

    • What holds atoms together in a molecule?

  • Gravitational forces
  • Chemical bonds (correct)
  • Electromagnetic forces
  • Nuclear forces

    • What is represented by a chemical formula?

    <p>The types and numbers of atoms in a molecule</p> Signup and view all the answers

    What occurs in a decomposition reaction?

    <p>A single compound breaks down into two or more simpler substances</p> Signup and view all the answers

    What is the result of the decomposition of water?

    <p>Hydrogen gas and oxygen gas</p> Signup and view all the answers

    What is the chemical equation for the decomposition of water?

    <p>2H2O → 2H2 + O2</p> Signup and view all the answers

    What occurs in a chemical reaction?

    <p>The breaking of chemical bonds and the formation of new chemical bonds</p> Signup and view all the answers

    What is a pure substance?

    <p>A material made of only one kind of matter</p> Signup and view all the answers

    What is a compound?

    <p>A substance made up of two or more different kinds of atoms chemically bonded together</p> Signup and view all the answers

    What is the difference between an element and a compound?

    <p>An element is made up of one kind of atom, while a compound is made up of two or more different kinds of atoms</p> Signup and view all the answers

    What is the chemical formula for water?

    <p>H2O</p> Signup and view all the answers

    What is the chemical formula for carbon dioxide?

    <p>CO2</p> Signup and view all the answers

    What is an example of an element?

    <p>Copper (Cu)</p> Signup and view all the answers

    What is an example of a compound?

    <p>Water (H2O)</p> Signup and view all the answers

    What is the term for the force that holds atoms together in a molecule?

    <p>Chemical Bond</p> Signup and view all the answers

    What is the primary reason for the difference in properties between a compound and its constituent elements?

    <p>The formation of chemical bonds</p> Signup and view all the answers

    What is the result of the breaking of chemical bonds in a chemical reaction?

    <p>The formation of simpler substances</p> Signup and view all the answers

    What is the purpose of a chemical formula?

    <p>To indicate the types and numbers of atoms in a molecule</p> Signup and view all the answers

    What is the difference between molecules composed of same kind of atoms and those composed of different kinds of atoms?

    <p>Their properties</p> Signup and view all the answers

    What is the role of protons and electrons in the formation of chemical bonds?

    <p>They attract each other</p> Signup and view all the answers

    What is the result of the formation of new chemical bonds in a chemical reaction?

    <p>The formation of new substances</p> Signup and view all the answers

    What is the characteristic of a molecule composed of oxygen and hydrogen atoms?

    <p>It is a liquid at room temperature</p> Signup and view all the answers

    What is the role of a chemical equation in a chemical reaction?

    <p>It represents the chemical reaction</p> Signup and view all the answers

    What is a characteristic of elements?

    <p>They exist as individual atoms or molecules made up of the same type of atoms</p> Signup and view all the answers

    Which of the following is an example of a pure substance?

    <p>Copper</p> Signup and view all the answers

    What is the main difference between elements and compounds?

    <p>Elements consist of only one kind of atom, while compounds consist of two or more kinds of atoms</p> Signup and view all the answers

    What is the term for a group of two or more atoms bonded together?

    <p>Molecule</p> Signup and view all the answers

    Which of the following substances consists of only one kind of atom?

    <p>Copper</p> Signup and view all the answers

    What is a characteristic of compounds?

    <p>They have a fixed ratio of atoms</p> Signup and view all the answers

    What is the fixed ratio of atoms in a compound?

    <p>Fixed</p> Signup and view all the answers

    What is true about the atoms in a molecule of oxygen?

    <p>They are chemically bonded</p> Signup and view all the answers

    What is the primary reason for the difference in properties between a compound and its constituent elements?

    <p>The formation of new chemical bonds</p> Signup and view all the answers

    Which of the following statements is true about molecules?

    <p>Molecules can be composed of same kind of atoms or different kinds of atoms</p> Signup and view all the answers

    What is the role of chemical formulae in chemistry?

    <p>To represent the types and numbers of atoms in a molecule</p> Signup and view all the answers

    What is the result of the breaking of chemical bonds in a chemical reaction?

    <p>The decomposition of the reactant</p> Signup and view all the answers

    What is the purpose of a chemical equation?

    <p>To represent the chemical reaction</p> Signup and view all the answers

    What is the result of the formation of new chemical bonds in a chemical reaction?

    <p>The formation of new substances</p> Signup and view all the answers

    What is the characteristic of a molecule composed of oxygen and hydrogen atoms?

    <p>It is a compound</p> Signup and view all the answers

    What is the role of protons and electrons in the formation of chemical bonds?

    <p>Protons attract electrons</p> Signup and view all the answers

    What is unique about the properties of an element?

    <p>They are fixed and distinct from those of its compounds.</p> Signup and view all the answers

    Why do elements exist as individual atoms or molecules?

    <p>Because they are made up of only one kind of atom.</p> Signup and view all the answers

    What is the relationship between the atoms in a compound?

    <p>They are chemically bonded in a fixed ratio.</p> Signup and view all the answers

    What is the main difference between the molecules of oxygen and carbon dioxide?

    <p>The type of atoms in each molecule.</p> Signup and view all the answers

    What is a characteristic of the atoms in a molecule of a compound?

    <p>They are of different kinds.</p> Signup and view all the answers

    What is a result of the chemical bonds between atoms in a molecule?

    <p>A change in the properties of the individual atoms.</p> Signup and view all the answers

    What is the purpose of a chemical formula in a compound?

    <p>To represent the ratio of atoms in a molecule.</p> Signup and view all the answers

    What is the difference between an element and a compound in terms of their chemical bonds?

    <p>Elements have chemical bonds between same kind of atoms, while compounds have chemical bonds between different kinds of atoms.</p> Signup and view all the answers

    What is the primary characteristic of an element?

    <p>It consists of only one kind of atom.</p> Signup and view all the answers

    What is the main difference between an element and a compound?

    <p>The type of atoms that make them up.</p> Signup and view all the answers

    What is the role of chemical bonds in a molecule?

    <p>They hold the atoms together in a molecule.</p> Signup and view all the answers

    What is the fixed ratio of atoms in a compound?

    <p>Fixed and dependent on the type of atoms.</p> Signup and view all the answers

    What is the result of the decomposition of a compound?

    <p>A simpler substance is formed.</p> Signup and view all the answers

    What is the characteristic of molecules composed of the same kind of atoms?

    <p>They are elements.</p> Signup and view all the answers

    What is the importance of understanding the difference between elements and compounds?

    <p>It is essential for studying chemistry.</p> Signup and view all the answers

    What is the main difference between the properties of a compound and its constituent elements?

    <p>The compound's properties are different from the individual elements.</p> Signup and view all the answers

    Which of the following molecules is composed of only two atoms?

    <p>O2</p> Signup and view all the answers

    What is the primary role of chemical bonds in a molecule?

    <p>To hold atoms together.</p> Signup and view all the answers

    What is the result of the decomposition of H2O?

    <p>2H2 + O2</p> Signup and view all the answers

    What is the purpose of a chemical formula?

    <p>To indicate the type and number of atoms in a molecule.</p> Signup and view all the answers

    What occurs during the formation of new chemical bonds in a chemical reaction?

    <p>Atoms are rearranged to form new substances.</p> Signup and view all the answers

    What is the role of protons and electrons in the formation of chemical bonds?

    <p>The attraction between protons and electrons forms bonds.</p> Signup and view all the answers

    What is a characteristic of a molecule composed of different kinds of atoms?

    <p>It is always a compound.</p> Signup and view all the answers

    More Like This

    Chemistry Basics
    10 questions

    Chemistry Basics

    LowRiskSwan avatar
    LowRiskSwan
    Chemistry Overview and Matter Classifications
    16 questions

    Chemistry Overview and Matter Classifications

    VisionaryChrysoprase8279 avatar
    VisionaryChrysoprase8279
    Classifications of Matter
    0 questions

    Classifications of Matter

    DeadOnPoltergeist avatar
    DeadOnPoltergeist
    Clasificación Básica de la Materia
    22 questions

    Clasificación Básica de la Materia

    PropitiousSugilite9551 avatar
    PropitiousSugilite9551
    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser