Matter & Properties
The two types of pure substances
How many protons, neutrons, and electrons in a neutral atom of fluorine?
Electrons - 9
Neutrons - 10
If an atom gains electrons it now has negative charge. These are called ____.
Anions
Name the ionic compound: KBr
Potassium bromdie
Name all the diatomic molecules
Hydrogen, Oxygen, Fluorine, Bromine, Iodine, Nitrogen, Chlorine
*never occurs on its own, it is always in a pair!
Evidence of chemical change
Color change
Temperature change
Gas production (bubbling, fizzing without boiling)
Formation of a precipitate (a solid appears in a liquid solution)
Light or sound
How many shells and valence electrons for Magnesium (Mg)
3 shells, 2 valence electrons
What is the general trend in reactivity for alkali metals as you go down the group?
Reactivity Increases
*Each element has an extra electron shell compared to the one above it, so the outermost electron is farther from the nucleus and feels a weaker attraction to it.
Is there a sharing or a transfer of electrons in this compound N2O4
Sharing - covalent compound
Ionic compounds - transfer electrons
Balance: __Al + __O₂ → __Al₂O₃
4Al + 3O₂ → 2Al₂O₃
Homogenous vs Heterogeneous
A homogeneous mixture is uniform throughout, while a heterogeneous mixture consists of clearly different parts or components.
Atomic number also represents what?
Number of protons and in a neutral atom, electrons
For which diagram do you only draw valence electrons
Lewis Dot Diagram
How would you name a polyatomic ion that has 2 less oxygen
Hypo___ite
Ex. Hyponitrite
H20 (l) → H2 (g) + O2 (g)
Balance and Classify
2H20 (l) → 2H2 (g) + O2 (g)
Decomposition
A pure substance is a type of matter in which all of the particles that make up the matter are ___
A pure substance is a type of matter in which all of the particles that make up the matter are identical
How to find # of neutrons?
# Neutrons = Atomic Mass (rounded) – Atomic Number (# Protons)
Which element has 11 protons, 11 electron, 12 neutrons?
Sodium (Na)
Metals on the periodic table which can form ions of different charges at different times
We call these multivalent metals
Complete and classify: AgNO₃ + NaCl →
AgNO₃ + NaCl →AgCl + NaNO₃; Double displacement
Explain the relationship between temperature and the changes of state
When heat is added, so is energy and the particles want to move more quickly and be farther apart
When heat is removed, so is energy and the particles want to move less quickly and be closer together
Which part of the atom is involved in bonding?
Valence Electrons
Why are noble gases considered unreactive?
Full valence shells—stable electron configuration
In an ionic compound, ___ tend to lose electrons, making them ___. And they become a ____.
In an ionic compound, metals tend to lose electrons, making them positive. And they become a cation. (postively charged ion)
What does a flame do in the presence of hydrogen, oxygen, carbon dioxide?
Hydrogen - Hear a pop
Oxygen - Flame will Reignite
Carbon Dioxide - Flame will go out