Download Atomic Structure Review/Learning Targets KEY

Learning Targets – Atomic Structure
(TEK 8.5A) Describe the structure of atoms, including the masses, electrical charges, and
locations of protons and neutrons in the nucleus and electrons in the electron cloud.
Define and explain what an atom is.
Atoms are the smallest unit of an element that maintains the properties of that element.
Identify the 3 sub-atomic particles that make up atoms.
Protons
Neutrons
Electrons
Define and explain what the atomic mass unit of an atom is.
Atomic Mass Unit
Identify the mass of each sub-atomic particle.
Protons and Neutrons have the same mass of about 1 amu.
Electrons are much smaller and have almost NO mass.
Identify the electric charge of each sub-atomic particle.
Protons are positive (+)
Neutrons are neutral (0 – No charge)
Electrons are negative (-)
Identify the location of each sub-atomic particle in the atom.
Protons and Neutrons are in the nucleus
Electrons are located around the nucleus in levels within the electron cloud.
Describe the nucleus of an atom and what makes it up.
The nucleus is the densely packed center of the atom that is made up of protons and neutrons.
Identify how to determine the mass of an atom.
Add the protons and neutrons together is determine the mass.
Explain what the electron cloud of an atom is and what makes it up.
The electron cloud is the area outside of the nucleus that is made up electrons moving quickly around on energy levels
Explain what the energy levels (orbitals/shells) are within the electron cloud and how many
electrons can fit on each level.
The 1st level can hold up to 2
The 2nd level can hold up to 8
The 3rd level can hold up to 8 or 18
Identify the charge of the nucleus, the charge of the electron cloud and the overall charge of an
atom and explain why.
The charge of the nucleus is positive because the protons have a positive charge and neutrons are neutral.
The charge of the electron cloud is negative because the electrons have a negative charge.
The overall charge of the atom is neutral or 0 because the protons and electrons cancel each other out.
Explain what A=P=E M-A=N represents and how to identify the # of each sub-atomic particle in
an atom.
Atomic # = Protons = Electrons
Mass – Atomic # = neutrons
Illustrate and label an Atomic Model of a lithium atom.
This model of Lithium has 3 protons, 4 neutrons, and 3 electrons.
Learning Targets – Protons and Valence Electrons
(TEK 8.5B) Identify that protons determine an element’s identity and valence electron
determine its chemical properties including reactivity.
Identify what determines an atoms identity.
The protons identify the element. This number will never change.
Explain how to determine what element an atom represents.
Count the number protons or electrons to determine the atomic number.
Explain what valence electrons are and how to identify them on an atomic model.
Valence electrons are the electrons found on the last energy level in an atom.
Identify what determines an atoms chemical properties including reactivity and explain why.
The number of valence electrons determines the chemical properties of the atom. Ex) 1 valence electron – HIGHLY
reactive; 8 valence electrons – not reactive/stable
Vocabulary
Atoms, Sub-Atomic Particles, Protons, Neutrons, Electrons, Nucleus, Electron Cloud,
Energy Levels/Orbitals/Electron Shells, Electric Charge, Positive Charge, Negative Charge, Neutral, Mass, Atomic
Mass Unit, Atomic Model, Bohr Model, Valence Electrons, Chemical Properties, Reactivity