Matter, Elements, Molecules, and Compounds By Cindy Grigg
What is matter? Matter is the stuff that makes up everything in the universe. Matter has mass and takes up space. Matter is made of atoms. Solids, liquids, gases, and plasma are all matter. When all atoms that make up a substance are the same, then that substance is an element. Elements are made of only one kind of atom. Because of this, elements are called "pure" substances. An atom is the smallest piece of an element that still has the properties of that element. For example, aluminum is a lightweight, shiny metal. If we took a piece of aluminum and cut it into small pieces, it would still be aluminum. It would still be a lightweight, shiny metal. The smallest piece would be called an atom. Atoms are so small they cannot be seen even with a microscope. Atoms consist of a nucleus that has protons and neutrons surrounded by electrons outside the nucleus. 1
Atoms of different elements can combine to make new substances. A molecule is formed when two or more atoms join together chemically. If atoms combine that are of two or more different elements, we call that a compound. All compounds are molecules, but not all molecules are compounds. When two hydrogen atoms combine with one oxygen atom, it becomes the compound water. The oxygen we breathe is actually two atoms of oxygen combined, so it is a molecule of oxygen. We use abbreviations for elements, molecules, and compounds. These abbreviations are called chemical symbols. The chemical symbol for an oxygen molecule is O2. 2
The compound water has a chemical symbol of H2O. This is like the "recipe" for water. It tells us that a water molecule is made of two atoms of hydrogen and one atom of oxygen. Oxygen is a gas that we can't see, hear, smell, taste, or feel. But it's in the air we breathe, and without it we would die. Hydrogen, also a gas, is the lightest substance on Earth. When two atoms of hydrogen join together with one atom of oxygen, those two gases make a liquid compound we call water. Water, a liquid at room temperature, is a very different substance from the two gases that it is made of. Many different compounds can be made when different atoms combine. 3
There are 93 elements that naturally occur on Earth. Many more have been made by scientists in a laboratory. With that many elements to form combinations, many millions of different molecules and compounds can be made. How is that possible? Think of our alphabet. The English alphabet has 26 letters. Those 26 letters can be combined in different ways to make millions of words. Atoms are like the letters of the alphabet and the compounds they make are like words. 4
Now that you have learned the language of chemistry, you are ready to learn more about elements, atoms, and the ways they combine. 5
Copyright © 2009 edHelper
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Date ___________________
Matter, Elements, Molecules, and Compounds 1. What is matter? The stuff that makes up everything in the universe Has mass and takes up space Is made of atoms Can be solid, liquid, gas, or plasma All of the above
2. What is an element? A pure substance Made of only one kind of atom Both A and B None of the above
3. What is an atom? 4. Atoms consist of ______. A metal A nucleus that has protons and The smallest piece of an element neutrons with electrons outside that still has the properties of that Solids element Gases A solid Two or more molecules A gas 5. Abbreviations for elements, molecules, 6. What is the chemical symbol for water? and compounds are called ______. O2 Abbr. H2O Chemical symbols Wa Letters NaCl Shorthand 7. How many elements naturally occur on 8. What is the lightest substance on Earth? Earth? 1,093 Water 26 Oxygen 93 Salt 102 Hydrogen
Name _____________________________
Date ___________________
Matter, Elements, Molecules, and Compounds Describe how a chemical symbol is like a recipe.
Matter, Elements, Molecules, and Compounds By Cindy Grigg
atom plasma elements universe hydrogen
molecule naturally substances element recipe
lightest compounds nucleus microscope atoms
lightweight mass substance molecules
Directions: Fill in each blank with the word that best completes the reading comprehension. What is matter? Matter is the stuff that makes up everything in the (1) _______________________ . Matter has (2) _______________________ and takes up space. Matter is made of atoms. Solids, liquids, gases, and (3) _______________________ are all matter. When all atoms that make up a substance are the same, then that (4) _______________________ is an element. Elements are made of only one kind of atom. Because of this, elements are called "pure" (5) _______________________ . An atom is the smallest piece of an (6) _______________________ that still has the properties of that element. For example, aluminum is a lightweight, shiny metal. If we took a piece of aluminum and cut it into small pieces, it would still be aluminum. It would still be a (7) _______________________ , shiny metal. The smallest piece would be called an atom. Atoms are so small they cannot be seen even with a (8) _______________________ . (9) _______________________ consist of a (10) _______________________ that has protons and neutrons surrounded by electrons outside the nucleus. Atoms of different elements can combine to make new substances. A molecule is formed when two or more atoms join together chemically. If atoms combine that are of two or more different (11) _______________________ , we call that a compound. All compounds are molecules, but not all molecules are compounds. When two hydrogen atoms combine with one oxygen (12) _______________________ , it becomes the compound water. The oxygen we breathe is actually two atoms of oxygen combined, so it is a molecule of oxygen. We use abbreviations for elements, molecules, and (13) _______________________ . These abbreviations are called chemical symbols. The chemical symbol for an oxygen (14) _______________________ is O2. The compound water has a chemical symbol of H2O. This is like the "(15) _______________________ " for water. It tells us that a water molecule is made of two atoms of hydrogen and one atom of oxygen. Oxygen is a gas that we can't see, hear, smell, taste, or feel. But it's in the air we breathe, and without it we would die. (16) _______________________ , also a gas, is the (17) _______________________ substance on Earth. When two atoms of hydrogen join together with one atom of oxygen, those
two gases make a liquid compound we call water. Water, a liquid at room temperature, is a very different substance from the two gases that it is made of. Many different compounds can be made when different atoms combine. There are 93 elements that (18) _______________________ occur on Earth. Many more have been made by scientists in a laboratory. With that many elements to form combinations, many millions of different (19) _______________________ and compounds can be made. How is that possible? Think of our alphabet. The English alphabet has 26 letters. Those 26 letters can be combined in different ways to make millions of words. Atoms are like the letters of the alphabet and the compounds they make are like words. Now that you have learned the language of chemistry, you are ready to learn more about elements, atoms, and the ways they combine. Copyright © 2009 edHelper
Name _____________________________
Date ___________________
Matter, Elements, Molecules, and Compounds 1. What is matter? The stuff that makes up everything in the universe Has mass and takes up space Is made of atoms Can be solid, liquid, gas, or plasma All of the above
2. What is an element? A pure substance Made of only one kind of atom Both A and B None of the above
3. What is an atom? 4. Atoms consist of ______. A gas Solids A solid Gases The smallest piece of an element A nucleus that has protons and that still has the properties of that neutrons with electrons outside element Two or more molecules A metal 5. Abbreviations for elements, molecules, 6. What is the chemical symbol for water? and compounds are called ______. NaCl Abbr. Wa Letters H2O Shorthand O2 Chemical symbols 7. How many elements naturally occur on 8. What is the lightest substance on Earth? Earth? 93 Water 1,093 Hydrogen 26 Oxygen 102 Salt
Matter, Elements, Molecules, and Compounds - Answer Key 1 2 3 4 5 6 7 8
All of the above Both A and B The smallest piece of an element that still has the properties of that element A nucleus that has protons and neutrons with electrons outside Chemical symbols H2O 93 Hydrogen
Matter, Elements, Molecules, and Compounds By Cindy Grigg
Answer Key What is matter? Matter is the stuff that makes up everything in the (1) universe . Matter has (2) mass and takes up space. Matter is made of atoms. Solids, liquids, gases, and (3) plasma are all matter. When all atoms that make up a substance are the same, then that (4) substance is an element. Elements are made of only one kind of atom. Because of this, elements are called "pure" (5) substances . An atom is the smallest piece of an (6) element that still has the properties of that element. For example, aluminum is a lightweight, shiny metal. If we took a piece of aluminum and cut it into small pieces, it would still be aluminum. It would still be a (7) lightweight , shiny metal. The smallest piece would be called an atom. Atoms are so small they cannot be seen even with a (8) microscope . (9) Atoms consist of a (10) nucleus that has protons and neutrons surrounded by electrons outside the nucleus. Atoms of different elements can combine to make new substances. A molecule is formed when two or more atoms join together chemically. If atoms combine that are of two or more different (11) elements , we call that a compound. All compounds are molecules, but not all molecules are compounds. When two hydrogen atoms combine with one oxygen (12) atom , it becomes the compound water. The oxygen we breathe is actually two atoms of oxygen combined, so it is a molecule of oxygen. We use abbreviations for elements, molecules, and (13) compounds . These abbreviations are called chemical symbols. The chemical symbol for an oxygen (14) molecule is O2. The compound water has a chemical symbol of H2O. This is like the "(15) recipe " for water. It tells us that a water molecule is made of two atoms of hydrogen and one atom of oxygen. Oxygen is a gas that we can't see, hear, smell, taste, or feel. But it's in the air we breathe, and without it we would die. (16) Hydrogen , also a gas, is the (17) lightest substance on Earth. When two atoms of hydrogen join together with one atom of oxygen, those two gases make a liquid compound we call water. Water, a liquid at room temperature, is a very different substance from the two gases that it is made of. Many different compounds can be made when different atoms combine. There are 93 elements that (18) naturally occur on Earth. Many more have been made by scientists in a laboratory. With that many elements to form combinations, many millions of different (19) molecules and compounds can be made. How is that possible? Think of our alphabet. The English alphabet has 26 letters. Those 26 letters can be combined in different ways to make millions of words. Atoms are like the letters of the alphabet and the compounds they make are like words. Now that you have learned the language of chemistry, you are ready to learn more about elements, atoms, and the ways they combine. Answers to Reading Comprehension Questions 1
All of the above
2 3 4 5 6 7 8
Both A and B The smallest piece of an element that still has the properties of that element A nucleus that has protons and neutrons with electrons outside Chemical symbols H2O 93 Hydrogen
