D a i l y S c i e n c e Day 1 Weekly Question What do atoms look like? Nearly everything in the universe is made of matter. This paper is made of matter. You are made of matter. Even the air we breathe is made of matter. But what is matter? Matter is anything that has both mass and volume. In other words, matter is any object or substance that is composed of particles and takes up space. The basic building blocks of matter are the elements. An atom is the smallest unit of an element that still has all the properties of that element. Oxygen is an element. Iron is an element. Gold and silver are both elements. There are 117 known elements, which means there are 117 types of atoms. More elements certainly exist, though they have yet to be discovered. A. Write true or false. 1. We know that only 117 elements exist. 2. The smallest unit of an element is an atom. 3. Gold and silver are made of atoms. 4. Atoms are the basic building blocks of matter. B. Even though it is invisible, air is composed of matter. In your own words, explain why this is true. C. Fill in the bubble next to the phrase that completes the analogy. Atom is to element as . A matter is to iron C matter is to element B element is to matter D element is to oxygen Vocabulary atom AT-um the smallest unit of an element that contains all the properties of that element elements EL-ih-mentz basic chemical substances from which all matter is made WEEK 1 Idea 5 Big © Evan-Moor Corp. EMC 5016 Daily Science 129 Name __________________________________________________________ D a i l y S c i e n c e Day 2 Weekly Question What do atoms look like? Although an atom is the smallest particle of an element, it is not the smallest particle of matter. Atoms are composed of even smaller particles called protons, neutrons, and electrons. A proton has a positive electric charge. An electron has a negative electric charge. And a neutron has no electric charge. Protons and neutrons are about the same size. Electrons, however, are much smaller. Atoms are identified by the number of protons they contain. For example, all atoms with eight protons are oxygen atoms. All atoms with 26 protons are iron atoms. Many atoms, such as oxygen, have the same number of neutrons as they do protons. Some atoms, such as iron, have more neutrons than protons. Only one kind of atom has fewer neutrons than protons. This is hydrogen, which contains one proton and no neutrons. In any atom, the number of electrons equals the number of protons, which makes the atom electrically neutral. A. Use the vocabulary words and the information in the passage to complete the paragraph. There are three basic rules for building an atom. First, the atoms of each type of element are defined by the number of they have. Second, excluding hydrogen, the number of is greater than or equal to the number of protons. And third, the number of is the same as the number of protons. B. Write true or false. 1. The smallest particle of matter is an atom. 2. Protons and electrons are roughly the same size. 3. An oxygen atom contains eight electrons. 4. Atoms are not electrically charged. Vocabulary electron ee-LEK-trahn a particle of matter with a charge of – 1 neutron NOO-trahn a particle of matter with a charge of 0 proton PRO-tahn a particle of matter with a charge of +1 WEEK 1 Idea 5 Big 130 Name __________________________________________________________