Name: _ Date: _ _
Student Exploration: Element Builder
Vocabulary: atom, atomic number, electron, electron dot diagram, element, energy level, ion,
isotope, mass number, neutron, nucleus, periodic table, proton, radioactive, valence electrons
Prior Knowledge Questions (Do these BEFORE using the Gizmo.)
1. What are some of the different substances that make up a pizza? _ _pizza
sauce dough
2. What substances make up water? two hydrogen and oxygen
3. What substances make up an iron pot? the element ion
Elements are pure substances that are made up of one kind of atom. Pizza is not an element
because it is a mixture of many substances. Water is a pure substance, but it contains two kinds
of atom: oxygen and hydrogen. Iron is an element because it is composed of one kind of atom.
Gizmo Warm-up
Atoms are tiny particles of matter that are made up of
three particles: protons, neutrons, and electrons. The
Element Builder Gizmo shows an atom with a single
proton. The proton is located in the center of the atom,
called the nucleus.
1. Use the arrow buttons ( ) to add protons, neutrons,
and electrons to the atom. Press Play ( ).
A. Which particles are located in the nucleus?
Protons and neutrons
B. Which particles orbit around the nucleus?
Electrons
2. Turn on Show element name. What causes the element name to change? Adding or
subtracting protons and neutrons.
, Get the Gizmo ready:
Activity A:
Use the arrows to create an atom with two protons,
Subatomic
two neutrons, and two electrons.
particles
Turn on Show element name.
Question: What are the properties of protons, neutrons, and electrons?
1. Observe: Turn on Show element symbol and Element
notation. Three numbers surround the element symbol: the
mass number (A), electrical charge (no number is displayed if
the atom is neutral), and the atomic number (Z).
2. Investigate: Watch how the numbers change as you add or
remove particles.
A. Which number is equal to the number of protons in the atom? Atomic number
B. How can you calculate the number of neutrons (N) in an atom? You subtract the
atomic mass by the amount of protons
C. Which particle (proton, neutron, or electron) has a positive charge? Proton
Negative charge? _neutron No charge at all? __electron
3. Analyze: An isotope is an alternative form of an element. Each isotope of an element has
the same number of protons, but a different number of neutrons. The isotope is represented
by the atomic symbol and mass number, such as He-4. Some isotopes are stable, while
others are radioactive, which means the atoms decay over time and emit radiation.
A. What are the stable isotopes of carbon? C-6
B. What are the stable isotopes of nitrogen? N-7
C. List two radioactive isotopes of oxygen: O-11 and O-26
4. Practice: Use the Gizmo to answer the following questions.
A. How many electrons are in a neutral atom of lithium? __3 electrons_ _
B. How many neutrons are in an atom of Mg-25? _13 neutrons_
C. What is the mass number of an atom with 5 protons and 7 neutrons? 12
D. When at atom is charged, it is called an ion. How many electrons are in O2-? 10
Student Exploration: Element Builder
Vocabulary: atom, atomic number, electron, electron dot diagram, element, energy level, ion,
isotope, mass number, neutron, nucleus, periodic table, proton, radioactive, valence electrons
Prior Knowledge Questions (Do these BEFORE using the Gizmo.)
1. What are some of the different substances that make up a pizza? _ _pizza
sauce dough
2. What substances make up water? two hydrogen and oxygen
3. What substances make up an iron pot? the element ion
Elements are pure substances that are made up of one kind of atom. Pizza is not an element
because it is a mixture of many substances. Water is a pure substance, but it contains two kinds
of atom: oxygen and hydrogen. Iron is an element because it is composed of one kind of atom.
Gizmo Warm-up
Atoms are tiny particles of matter that are made up of
three particles: protons, neutrons, and electrons. The
Element Builder Gizmo shows an atom with a single
proton. The proton is located in the center of the atom,
called the nucleus.
1. Use the arrow buttons ( ) to add protons, neutrons,
and electrons to the atom. Press Play ( ).
A. Which particles are located in the nucleus?
Protons and neutrons
B. Which particles orbit around the nucleus?
Electrons
2. Turn on Show element name. What causes the element name to change? Adding or
subtracting protons and neutrons.
, Get the Gizmo ready:
Activity A:
Use the arrows to create an atom with two protons,
Subatomic
two neutrons, and two electrons.
particles
Turn on Show element name.
Question: What are the properties of protons, neutrons, and electrons?
1. Observe: Turn on Show element symbol and Element
notation. Three numbers surround the element symbol: the
mass number (A), electrical charge (no number is displayed if
the atom is neutral), and the atomic number (Z).
2. Investigate: Watch how the numbers change as you add or
remove particles.
A. Which number is equal to the number of protons in the atom? Atomic number
B. How can you calculate the number of neutrons (N) in an atom? You subtract the
atomic mass by the amount of protons
C. Which particle (proton, neutron, or electron) has a positive charge? Proton
Negative charge? _neutron No charge at all? __electron
3. Analyze: An isotope is an alternative form of an element. Each isotope of an element has
the same number of protons, but a different number of neutrons. The isotope is represented
by the atomic symbol and mass number, such as He-4. Some isotopes are stable, while
others are radioactive, which means the atoms decay over time and emit radiation.
A. What are the stable isotopes of carbon? C-6
B. What are the stable isotopes of nitrogen? N-7
C. List two radioactive isotopes of oxygen: O-11 and O-26
4. Practice: Use the Gizmo to answer the following questions.
A. How many electrons are in a neutral atom of lithium? __3 electrons_ _
B. How many neutrons are in an atom of Mg-25? _13 neutrons_
C. What is the mass number of an atom with 5 protons and 7 neutrons? 12
D. When at atom is charged, it is called an ion. How many electrons are in O2-? 10
