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READING MATERIAL
Read About Atoms & Molecules
WHAT IS ATOMIC STRUCTURE?
All atoms are made of three smaller particles called protons, neutrons and electrons. The protons and neutrons clump together at the center of an atom and the electrons orbit far away. Atoms can be combined to form molecules through chemical reactions. To better understand atomic structure…
LET’S BREAK IT DOWN!
Atomic Structure
The center of the atom, often referred to as the nucleus, is made up of protons and neutrons. The protons are positively charged, while the neutrons don’t have a charge. Orbiting around the outside of the atom at a tremendous speed and distance are electrons. Electrons are the smallest of the three subatomic particles and have a negative charge. Empty space is found between the atomic nucleus and electrons.
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Microscopic Atoms
Atoms are extremely small. Atoms are more than 10,000 times smaller than the width of a hair. Even a classroom microscope would not be able to see anything close to the size of an atom. A specialized microscope called a Scanning Tunneling Microscope developed in the 1980s can show us individual atoms. If you were to look at some iron filings with a Scanning Tunneling Microscope, you would be able to see tiny spheres of iron atoms.
Identifying Atoms
Each element has a certain number of protons, neutrons and electrons. We can find this information by referencing the Periodic Table of Elements. For example, element number 6 on the table is carbon, which is notated by the letter C. The periodic table also shows us that carbon’s atomic number is 6. The atomic number tells us how many protons and electrons are present in the element. From this information we know that carbon has 6 protons and 6 electrons.
Atom The basic unit of an element. All matter is made up of atoms.
Proton A positively charged subatomic particle located at the center of an atom.
Neutron A subatomic particle with no charge located at the center of an atom.
Electron A subatomic particle of an atom that is negatively charged and orbits the nucleus extremelyfast.
Nucleus Protons and neutrons clump together at the center of an atom to form the nucleus of an atom.
ATOMS & MOLECULES DISCUSSION QUESTIONS
What would you see if you looked at iron filings with a Scanning Tunneling
Microscope?
Since the Scanning Tunneling Microscope is so powerful, you would see tiny spheres which are iron atoms (the smallest possible unit of iron).
Describe the different particles that make up an atom.
An atom is made up of 3 particles; protons, neutrons and electrons. Protons are positively charged and are positioned in the center of an atom. Neutrons are not charged and are also located in the center of an atom. Electrons orbit the center very quickly and are negatively charged.
What are some examples of elements? How do you know they are elements?
Some examples of elements are gold, iron, copper and carbon. Anything on the periodic table is an element. All elements are pure substance made up of only one type of atom.
How can you use the Periodic Table of Elements to help you find information
about specific elements?
The Periodic Table of Elements shows the names and abbreviations for each element. It also tells you how many protons, neutrons and electrons each atom has. The atomic number of each element corresponds with how many protons and electrons an element has. We cover more details about the periodic table in our lesson called “The Periodic Table.”
How did scientists conclude that most of an atom is empty space?
In 1908, Ernest Rutherford did an experiment where he shot beams of radiation through gold foil which is made up of gold atoms. Most of the radiation went right through the gold foil, while only a tiny fraction of the beams bounced back. This supports the atomic model with most of the mass at the center with electrons orbiting far away from it.
What are some different careers available for people that want to study
atoms and molecules?
Scientists in the medical field use molecules on a regular basis to develop new medicines to help fight diseases. Specifically, biomedical scientists may be able to replicate naturally occurring molecules to help people with deficiencies.
