1. Chapter Two In Dragonfly Book
Matter
Chapter Two
In Dragonfly Book

2. What is the basic building block of all matter?
The atom

3. Atoms consist of what three subatomic particles?
_______- located ______ the nucleus, with a _______ charge.
________- located _____ the nucleus, with ___ charge (neutral)
________- move around the outside of the nucleus, with a ________ charge.
Protons
inside
positive
Neutrons
inside no
Electrons
negative

4. What is the atomic number?
The number of _______ in one atom of that element.
Located on the Periodic Table.
Ex- Hydrogen: ____ Ex- Oxygen: ____ Ex-Helium: ____
protons 1 8 2

5. What is the atomic mass?
The number of _______ + ________ in one atom of that element.
Located on the Periodic Table.
protons
neutrons

6. Atomic Mass – Atomic Number = the number of neutrons
How do you use the Periodic Table to determine the number of neutrons for an element?
Easy….just _______!!
Atomic Mass – Atomic Number = the number of neutrons
Ex- Fluorine has an atomic number of 9. It has an atomic mass of 19. So, it has 19 – 9 = ____ neutrons. It has ___ protons (so it must also have ___ electrons).
subtract 10 9 9

7. Use the periodic table provided to complete this chart on your notes.
Element
Number of Protons
Number of Neutrons
Number of Electrons
Hydrogen
Nitrogen
Phosporus

8. What is an energy level?
Regions of space around the atom nucleus that hold the _________.
Also called _______.
1st energy level holds ___ electrons
2nd energy level holds ___ electrons
3rd energy level holds ___ electrons
electrons
orbitals 2 8 18

9. What are valence electrons?
The electrons found on the __________ shell.
The atom is “happy” (stable) when its valence shell is ____ (2, 8, or 8/18)
outermost
full

10. What happens when an atom is NOT “happy”?
It will form a ____ with another atom that is not happy!
Covalent bonds: 2 or more atoms _____ electrons
Ionic bonds: 1 atom _______ electrons to another atom
bond
share
transfer