Download What are the parts of an atom?

What are the parts of an atom?
As you have learned, an atom can be divided into smaller parts. That’s because atoms themselves are composed of particles even
smaller then themselves. The parts are called protons, neutrons, and electrons.
Protons and neutrons are found in the center of an atom, called the nucleus. These particles are very tightly packed and held together by what scientists call the ‘Strong Nuclear Force”. Protons within the nucleus have a positive (+) electric charge. The neutrons have no charge, or are neutral.
The electrons are found outside the nucleus of an atom. They orbit the nucleus, much like the moon orbits the Earth. Unlike, the
moon, however, the electrons move at such great speed that it is impossible to see them. If the moon orbited the Earth at the
same velocity, it would appear to be a solid ring, instead of an individual object.
The area in which the electrons orbit is called the electron cloud. There is space in between the electrons, and they orbit at specific
levels, or distances from the nucleus. Electrons are much smaller than protons or neutrons, and have a negative (-) charge.
When looking at a periodic table, you may notice that each element has an individual number from 1 to
118. For example, copper, shown at left, has the number 29. This is called the atomic number of copper.
The atomic number tells you that copper has 29 protons in its nucleus. This also tells you that copper has
29 electrons because the number of protons is equal to the number of electrons in an atom. The number
that has a decimal or is in parentheses is called the atomic weight. The atomic weight is the number of protons plus the number of neutrons in the nucleus of an atom. To determine the number of neutrons, first
you round the atomic mass. For example, copper’s atomic mass of 63.546 would round to 64. Next, you
subtract the number of protons from the rounded atomic mass. This will give you the number of neutrons in that atom. Copper
has 35 neutrons in its nucleus. (64-29=35). The number of neutrons can vary in an element, this will be discussed later on.
This diagram shows you the basic structure of an atom.
The protons and neutrons are located in the nucleus, and the electron orbits the
nucleus in the electron cloud.
Diagrams can help us understand atoms. Study the diagram of Lithium and then answer the questions.
1) What particles are found in the nucleus?
2) How many protons does lithium have?
3) How many electrons does lithium have?
This diagram represents a boron atom.
1) How many electrons does boron have?
2) What would the atomic number of boron be?
3) How many neutrons does boron have?
This diagram represents an element on the periodic table.
1) What is the name of the element?
2) How many protons does this element have?
3) How many electrons does this element have?
This diagram represents a hydrogen atom. Hydrogen is the lightest and most simple element..
1) How many protons does Hydrogen have?
2) How many neutrons does hydrogen have?
3) What would the atomic mass of hydrogen be?
Questions:
1) All matter is made up of tiny parts called ____________.
2) The center of an atom is called the ______________.
3) The particles found in the nucleus of an atom are called ______________ & ________________.
4) The electron cloud is where the _______________ orbit the nucleus of an atom.
5) Protons have a ______________ charge.
6) Neutrons have a ______________ charge.
7) Electrons have a ______________ charge.
8) The ________________________________ holds the nucleus of an atom together.