Review Atoms: Nucleus Proton Neutron Electron

Basic parts of atoms are: Protons + Neutrons / Electrons -

Atom’s parts are: 2 1 3

Activity Become an Oxygen atom 8 students in the center are Protons 8 students in the center are Neutrons 8 students orbit around the nucleus (2 inner ring and 6 outer ring)

When atoms that are attracted to one another get close, they may bond together to form a molecule. Carbon atom Hydrogen atom

When molecules stick to each other, they form long chains called polymers.

How Atoms and Molecules Bond

"Happy Atoms" The idea behind Happy Atoms is that each atom wants a certain number of electrons in their outermost orbital. Some atoms have too many electrons (one or two extra). These atoms like to lose their electrons. Some atoms are really close to having a full orbital; those atoms go around gaining from other atoms that want to give up an electron. Why atoms bond together?

Atoms form covalent bonds by sharing electrons with other atoms. Bonding

A covalent bond is stronger and holds the atoms in a molecule together. A Hydrogen bond is weaker and it attracts molecules to one another.

Covalent bonds are strong bonds that hold atoms in a molecule together. The electrons orbit around both nuclei, holding the atoms together. A covalent bond happens between atoms that share electrons.

Hydrogen bonds are weak bonds that attract molecules to one another.

Which of these molecules will bond? 1 2 3

Magnet demo!

This is what DNA looks like. The white parts represent the two different strands. These strands can be separated.

Next: DNA