Learning Outcomes for test #11
Unit 1, Lesson 1
Name: ____________________________________
Test Date: _________________________________
Students need to learn and understand the meaning of the following vocabulary words AND be able to
apply them to a variety of situations.
1. matter- anything that has mass and takes up space
2. element- a material that cannot be broken down into any simpler substance through
chemical reactions
3. atom- the smallest unit of an element that has the properties of that element
4. nucleus- the center of an atom, containing most of its mass
5. proton- a particle in the nucleus of an atom that carries one unit of positive electrical
charge
6. neutron- a particle in the nucleus of an atom that has no electric charge
7. electron- a particle in the space outside the nucleus of an atom that carries one unit of
negative electric charge
8. molecule-a particle that contains more than one atom joined together
Students will learn in class about the following topics. Be prepared to be assessed on them.
1. Atoms are the building blocks that make up all matter. Atoms are the smallest units of
elements. All matter is made of elements.
2. A property is something that can be observed about an object or a group of objects. One
important property of elements is the state of matter at room temperature.
3. Metals are elements that share common properties such as shiny luster, conductivity, and
flexibility. Nonmetals are elements that are poor conductors, dull, and brittle. Some elements
have properties between metals and nonmetals. They are called metalloids.
4. If you cut a piece of an element in half, will it still be an element? Yes, the two halves have
the same properties.
5. In 1803, John Dalton proposed that elements are made of tiny particles that cannot be cut into
smaller pieces. These particles are called atoms. An atom is the smallest unit of an element
that retains the properties of that element.
6. The nucleus is the center of an atom. It is made of protons and neutrons. Protons are
particles with one unit of positive electric charge each. The number of protons in an atom is
called the atomic number and determines which element it is. Neutrons are particles with no
electric charge- they are neutral.
7. Atoms also contain electrons, which are smaller particles with one unit of negative electric
charge each. They move within the space outside the nucleus. Most of an atom is empty space.
Usually, the number of protons and electrons are equal, so atoms have no overall charge.
8. How do scientists determine the atomic mass of an atom? The atomic mass is the sum of the
mass of the protons and the neutrons in an atom. For example, in an oxygen atom, there
are 8 protons and usually 8 neutrons, so its atomic mass is about 16 amu.
9. How are atoms and molecules different? Atoms are the smallest particle of an element.
Molecules are formed from two or more atoms; they often have different properties than
the atoms that form them.
10. Most of the atoms in the world exist as part of a molecule, not on their own. Objects are just
many molecules grouped together. When a molecule forms from elements, atoms link together
through their electrons. This causes molecules to have different properties from their
element.
11. Molecules can be made up of atoms from different elements. For example, water is made up
of two hydrogen atoms and one oxygen atom.
12. How does atomic mass differ from atomic number? Atomic mass is the sum of the mass of
the protons and neutrons; the atomic number is the number of protons.
13. What are some properties used to classify elements? whether they are reactive; whether
they are solid, liquid, or gas at room temperature; whether they are metal, metalloid, or
nonmetal
14. Who created the periodic table? Dmitri Mendeleev
15. It is called the periodic table because the properties repeat in cycles, or periods. There are
three main groups on the periodic table: metals, metalloids, and nonmetals
16. Elements are arranged by their atomic numbers in the periodic table. The atomic number is
related to the mass of each element. Each element has a symbol with one, two, or three lettersfirst letter capital; second and third letters are lowercase.
17. Each column in the periodic table contains elements with similar chemical properties.
18. Be able to answer questions by looking at a periodic table: For example, how many
more protons are there in a chlorine atom than in an oxygen atom? 9
19. Why is an electron microscope important in studying atoms? An atom is too small to see
with an ordinary light microscope. An electron microscope uses electrons to examine a
sample.
20. How can scientists observe atoms? Scientists use devices such as electron microscopes and
scanning tunneling microscopes to create images of atoms.
21. What particles in an atom can increase or decrease in number without changing the identity
of the element? The number of protons in an atom determines which element it is. So that
cannot change. The number of neutrons or electrons in an atom can change without
changing the identity of the element.
22. Niels Bohr’s model of an atom looked like a solar system.