Elements• A pure substance that consists of just one type of
atom
• Classified by the number of protons/electrons
Elements• A pure substance that consists of just one type of
atom
• Classified by the number of protons/electrons
• REMEMER– the number of PROTONS is EQUAL to the number of electrons!!
Elements• A pure substance that consists of just one type of
atom
• Classified by the number of protons/electrons
• REMEMER– the number of PROTONS is EQUAL to the number of electrons!!
• Atoms have NO CHARGE… NEUTRAL
Chemical Compounds
• 2 or more elements combined
• Example- H2O– Hydrogen Hydrogen Oxygen
• Elements “combine” to one another by chemical bonding
Chemical Bonding
• When 2 or more elements bond together, the result is often very different than the original elements
• Bond- join, combine, or come together• Original- what you started with
Chemical Bonding
• Elements bond together, or combine/join with other elements by stealing or sharing electrons from other elements.
• Chemical bonds happen because of electrons
CHALLENGE
What do you think the charge of the sodium atom and the charge of the chlorine atom is Now that they are bonded? Why?
What do you think the charge of the sodium atom and the charge of the chlorine atom is now? Why?
CHALLENGE
REVIEW
• What is an atom?
• What are the 3 subatomic particles?
• What is the overall charge of an atom, and why?
Review
• What is an element?• What does the “atomic” number tell us?• What are some examples of elements?
REVIEW
• How does chemical bonding happen? (what does it involve?)
• What are the 2 types of chemical bonds we have learned about?