Atoms, Periodic Table

Neon has 10 protons and 10 electrons. The electrons fill the energy levels in Neon like this:

2 in the first, and 8 in the second

Protons are located in the nucleus of the atom. A proton has

A positive charge

An element and an atom are different but related because

An element is made up of all the same type of atom

4. How is it that different atoms of the same element can have slightly different atomic masses?

Atoms of the same element all have the same number of protons but they can have different numbers of neutrons. This is why different atoms of the same element can have different atomic masses.

An electron is in a region outside the nucleus. An electron

Has less mass than a proton and has a negative charge

2. When you charged a strip of plastic by rubbing it through your fingers or on cloth, you actually transferred electrons onto the plastic strip. Using the terms "electrons" and "protons", and "negative" and "positive", explain why the strip was attracted to your fingers or the cloth you rubbed it on.

If electrons were transferred to the plastic, the plastic has extra electrons and becomes negative, since electrons are negative. If my fingers lost electrons, they would have more protons than electrons and become positive. Positive and negative attract.

The atoms of the same element can have different isotopes. An isotope of an atom

Is an atom with a different number of neutrons

Electrons are in regions around the nucleus called energy levels. The first energy level

Is closest to the nucleus

7. Magnesium's atomic number is 12. Magnesium's atomic mass is 24.30. If all magnesium atoms had 12 neutrons, its atomic mass would be about 24.00. If all magnesium atoms had 13 neutrons, its atomic mass would be about 25.00. Explain why the atomic mass of magnesium is between 24 and 25.

It is because some magnesium atoms have 12 neutrons and some have 13 neutrons. These are different isotopes of magnesium. The atomic mass is the average of these different isotopes so it is a number between 24 and 25.

Neutrons are in the nucleus of the atom. A neutron has

No charge

6. If you know the atomic number of an element in the periodic table, do you also know the number of neutrons in any atom of that element? Explain.

No, because different atoms of the same element can have different numbers of neutrons. These are called isotopes.

A hydrogen atom is made up of one proton and one electron. The proton and electron stay near each other because

Positive and negative charges attract

3. When you rub a balloon on your hair, electrons are transferred onto the balloon. Using the terms "electrons" and "protons", and "negative" and "positive", explain why a rubbed balloon is attracted to and sticks to a wall even though you didn't rub the balloon on the wall.

Since the balloon has extra electrons from being rubbed on your hair, the balloon is negatively charged. When you bring it over to the wall, the negative balloon repels the negative electrons in the wall and leaves an area of positive charge. The negative balloon is then attracted to the positive wall.

The periodic table shows that a carbon atom has six protons. This means that a carbon atom also has

Six electrons

5. What is the difference between the atomic number and atomic mass of an element in the periodic table?

The atomic number is the number of protons in the nucleus of the atoms in that element. The atomic mass is the average mass of the different isotopes of that element.

The atomic mass of an element is

The average mass of all the isotopes of the element

8. What are the "energy levels" of an atom?

The energy levels of an atom are the regions around the atom where electrons are likely to be found. The different energy levels hold a different number of electrons.

The atomic number of an atom is

The number of protons

The atoms in a column of the periodic table all have

The same number of electrons in the outer energy level

1. What are the three common subatomic particles? Where are they found within an atom? What charge do they have?

The three common particles are protons, neutrons and electrons. Protons and neutrons are found in the atom's nucleus and electrons are in regions outside the nucleus. Protons have a positive charge, electrons have a negative charge, and neutrons have no charge.