1. Protons, neutrons, electrons

2. Pencil Zoom The “lead” of a pencil is actually made of a substance called graphite which is made of carbon atoms. The picture shows a close-up of one carbon atom.

3. What are the three different tiny particles that make up an atom? Protons, neutrons, and electrons.

4. Which of these is in the center of an atom? Protons and neutrons are in the center (nucleus) of the atom. Hydrogen is the only atom that usually has no neutrons. The nucleus of most hydrogen atoms is composed of just 1 proton.

5. What zooms around the nucleus of an atom? Electrons

6. Which one has a positive charge, a negative charge, and no charge? Proton—positive; electron—negative; neutron—no charge. The charge on the proton and electron are exactly the same size but opposite. The same number of protons and electrons exactly cancel one another in a neutral atom.

7. Two protons repel each other and that two electrons repel each other. But a proton and an electron attract each other. Another way of saying this is that the same or “like” charges repel one another and opposite charges attract one another.

8. Since opposite charges attract each other, the negatively charged electrons are attracted to the positively charged protons. This attraction is what holds the atom together.

9. Protons and Electrons Protons have a positive charge. Two protons repel each other. Electrons have a negative charge. Two electrons repel each other. A proton and an electron have opposite charges and attract each other. file:///C:/Users/Amy/Downloads/protons_and _electrons.swf

10. Hydrogen Atom A hydrogen atom has one proton as the nucleus and one electron in the region outside the nucleus. The electron and proton are attracted to each other. This attraction holds the atom together. It is not possible to locate the exact position of an electron but the electron cloud shows the region where an electron is most likely to be.

14. Charged Plastic and Hand When the plastic strip is rubbed on the skin, electrons from the skin are transferred to the plastic giving the plastic a negative charge. When the plastic is moved near the desk, electrons in the desk are repelled by the negatively charged plastic. This leaves an area of positive charge in the desk near the plastic. The negative plastic and the positive area of the desk attract.

15. Plastic and Skin

16. Plastic and Desk

17. Plastic and Plastic

19. Balloon and Water When the balloon is rubbed on hair or clothes, electrons move onto the balloon giving it a negative charge. When the negatively charged balloon is brought near the water, electrons are repelled and move away from the balloon, leaving a positive area of the water near the balloon. The negatively charged balloon and the positive area of the water attract.