1 Lesson: BIO.A.1.2.2 Reactions, Atoms, and Ions

1 Lesson: BIO.A.1.2.2

• Atoms bouncing off of each other and making or breaking bonds:

• Physical reaction: change structure but same matter

• Chemical reaction: what you start with the atoms rearrange creating a different product

Atom Parts

• Proton = Positive

• Neutron = Neutral

• Electrons = Negative

• Nucleus contains the neutron and proton the mass of the atom.

• Number of protons identifies the atom (Atomic Number)

ATOMS want to be stable.

• To be stable, outer shell needs to be full.

• First shell can only hold 2 electrons

• Next shells need 8 electrons.

• Mg giving away two electrons it now has a full outer shell.

• Atom need to give or take electrons to become stable.

Ion

• An atom that loses or gains a electron

• Losing or gain electrons results in different number of protons and neutrons creating a charge. (-) Anion and (+) Cation

How is an Ion Created?

• Atom want to be stable with a full outer shell of electrons of 2 first shell or 8 for the other shells.

• Fluorine needs one more electron to have (8) electrons in outer shell.

Fluorine will take an electron from a weaker atom so it will have 8.

• Resulting in more electrons than protons making it negative.

Reactants and Products

• Reactant: substance present at the start of a chemical reaction

• Product: substance that is present at the end of a chemical reaction

Energy: Exothermic or Endothermic Reaction

• All reactions take energy.

• Energy is conserved in chemical reaction meaning it never gets destroyed.

• Endothermic the reaction is cooler than the surroundings.

• Exothermic the reaction is hotter than surroundings.

Multiple Choice

What do atoms that form positive ions tend to do?

• Tend to lose electrons

• Tend to lose protons

• Tend to gain electrons

• Tend to gain protons

Multiple Choice

Which of these is the electron?

• A
• B
• C
• D

Multiple Choice

Particles in an atom that are neutral and have no charge are 

• negatrons 
• electrons 
• neutrons 
• protons 

Multiple Choice

Cations are

• negative ions
• gained electrons
• positive ions
• inner shell electrons

Multiple Choice

a chemical reaction that releases energy by light or heat

• Endothermic Reaction
• Exothermic Reaction
• Diffusion
• Fission

Multiple Choice

A process or reaction in which the system absorbs energy from its surroundings; usually, but not always, in the form of heat

• Endothermic Reaction

• Exothermic Reaction

• Diffusion

• Fission

Multiple Choice

One element loses an electron to another

• Share Electrons

• Transfer Electrons

Multiple Choice

Both elements in a compound share a certain number of electrons

• Share Electrons

• Transfer Electrons

Multiple Choice

An atom or molecule which has gained or lost one or more of its valence electrons

• Covalent Bond

• Chemical Formula

• Ion

• Compound

Multiple Choice

A substance that is formed as the result of a chemical reaction

• Product

• Reactant

• Starters

• Enders

Multiple Choice

The starting materials in a chemical reaction

• Products

• Reactants

• Starters

• Enders