U.2 Chem Flashcards
(24 cards)
Why are atoms neutral?
They have equal protons and electrons.
Why are ions charged?
They gain or lose electrons.
What happens when a sodium (Na) atom becomes an ion?
It loses 1 electron, becoming Na⁺ (11 protons, 10 electrons).
How does a calcium ion (Ca²⁺) form?
It loses 2 electrons, becoming a positive ion (cation).
How do molecules and ionic compounds differ?
Molecules share electrons (covalent bonds).
Ionic compounds transfer electrons (ionic bonds).
Why do ionic compounds form crystals?
Positive and negative ions attract, forming a lattice pattern.
How do nonmetals form covalent bonds?
They share electrons to become stable.
What are molecular compounds made of?
Nonmetals with covalent bonds (electrons are shared).
They always form in pairs.
What does a Bohr-Rutherford diagram resemble?
A solar system (nucleus in the center, electrons in shells).
What are the common element colors in B-R diagrams?
- H (Hydrogen) → White
- C (Carbon) → Black
- O (Oxygen) → Red
- N (Nitrogen) → Orange
- Hydrogens in molecules → Green
What does one spring (line) in a diagram represent?
One covalent bond.
What are ions?
Charged particles that gain or lose electrons.
What makes an atom neutral?
Protons (+) = Electrons (-).
What happens to protons when an atom becomes an ion?
They stay in the nucleus; only electrons move.
Which groups contain metals?
Groups 1, 2, 3.
How do metals form ions?
Give away valence electrons → Become positively charged (Cations).
Which groups contain nonmetals?
Groups 15, 16, 17.
How do nonmetals form ions?
Gain electrons to fill their valence shell → Become negatively charged (Anions).
How do ionic compounds form?
Metals + Non-Metals → Transfer electrons to form ions.
Why are ionic compounds neutral?
Total positive charge = Total negative charge.
Metals → Lose electrons → Positive ions (Cations).
Non-Metals → Gain electrons → Negative ions (Anions).
Where are molecular compounds found on the P.T.?
Groups 14, 15, 16, 17.
Where are metals located?
Groups 1, 2, 13 → Form positive charges.
How do non-metals form negative ions?
They gain electrons to complete their valence shell.
If an element is in Period 3, what does it tell u about its structure?
If an element is in Group 16, what does it tell u about its structure?
Period 3 → This means it has 3 electron shells.
Group 16 → This means it has 6 valence electrons.
