Batteries

Where it all started.

The invention of the battery as we know it is credited to the Italian scientist Alessandro Volta, who put together the first battery to prove a point to another Italian scientist, Luigi Galvani. In 1780, Galvani had shown that the legs of frogs hanging on iron or brass hooks would twitch when touched with a probe of some other type of metal. He believed that this was caused by electricity from within the frogs’ tissues, and called it ‘animal electricity’.

Image source: Luigi Galvani / Wikimedia Commons.

​

Luigi Galvani's frog experiment

Volta, believed that the electric current came from the two different types of metal. He stacked of layers of silver and zinc interspersed with layers of cloth or paper soaked in saltwater, and found that an electric current did in fact flow through a wire applied to both ends of the pile.

​

Alessandro Volta's Battery

• a cathode (+)

• an anode (-)

• an electrolyte

The cathode (positive end) and anode (negative end) are hooked up to an electrical circuit

Batteries have 3 parts...

​

Multiple Choice

What two portions of a battery react to produce electrons?

• Anode and Cathode

• Cathode and Electrolyte

• Anode and Electrolyte

• Cathode and Electrons

• an energy source

  • which provides the "push"; volts

• the load

  • which converts electrical energy to another form of energy

• the wires

  • which connect the source and load together

• the switch​

  • which opens and closes the circuit

Circuits have 4 parts...​

2 Types of Batteries:

1. Dry Cell - traditional batteries; uses a paste electrolyte with enough moisture to allow current to flow

2. Wet Cell​ - electric battery device consisting of 2 or more electrochemical cells that convert chemical energy into electrical energy using a liquid electrolyte

Batteries and Electrical Circuits

​

the electrolyte is not really dry; it is a paste

• these are your standard AA, C, and D type batteries

• the (+) terminal is made of carbon​

Dry Cell

the electrolyte is a liquid

• example: car battery

  • the electrolyte here is sulfuric acid​

Wet Cell

Multiple Choice

Which of the following choices represent the three components of a battery?

• Anode, electrons, and wires

• protons, electrons, and neutrons

• Anode, cathode, and electrolyte

• AC, DC, and Electrons

Schematic Diagrams are pictures that we can use to show circuits in a simple way.

• they use symbols like the ones in the top right image to represent the parts of a circuit

Circuit Diagrams Practice

​

Multiple Choice

How many chemical reactions take place in a typical battery?

• 1

• 2

• 3

• 4

the circuit's pathway is broken

• meaning the switch is open or a part of the circuit is disconnected and electrons cannot flow to the load.

  • has "breaks" in the circuit​

​​Open Circuit (no light)​

the circuit path is complete, meaning that the switch is closed and electrons are allowed to flow

• each part of the circuit is connected​

​​Closed Circuit (light)​

​Lightbulb

Schematic Diagrams are pictures that we can use to show circuits in a simple way.

• they use symbols like the ones in the top right image to represent the parts of a circuit

Circuit Diagrams Practice

​

Multiple Choice

What reaction occurs at the anode?

• Ag⁺ + e^- →Ag

• Ag → Ag⁺ + e^-

• Ni²⁺ + 2e^- → Ni

• Ni → Ni²⁺ + 2e^-

Multiple Choice

Which statement is correct when the cell produces electricity?

• Magnesium atoms lose electrons

• Mass of the iron electrode decreases.

• Electrons flow from the iron half-cell to the magnesium half-cell.

• Negative ion flow from magnesium half-cell to iron half-cell

Multiple Choice

What is the function of Y in cell below?

• To complete the circuit

• To allow flow of electrons between both cells

• To allow flow of ions 

• To connect both half cells

Multiple Choice

Oxidation happens at the

• anode

• cathode

• salt bridge

• voltmeter

Multiple Choice

This electrode in a voltaic cell gains mass

• anode

• cathode

Multiple Choice

In which direction does electricity flow in a voltaic cell (battery)?

• Electrons flow from the cathode to the anode

• Electrons flow from left to right

• Electrons flow from anode to cathode

• Electrons flow from right to left

Multiple Choice

In a rechargeable battery that is half used, what would be the conditions in the battery?

• All of the electrons would be in the anode

• Some of the electrons would be in the cathode and anode

• The electrons would be found in the electrolyte

• All of the electrons would be in the cathode.

Multiple Choice

What is the main difference between AC current and DC current?

• the electrons in AC current flow completely through the circuit

• the electrons in an AC circuit stay on one stationary place

• the electrons in AC move back and forth, but not through the complete circuit

• electrons are consumed by the circuit in AC but not DC

Multiple Choice

In a rechargeable battery, what happens when a dead battery is plugged into a charger and electrical outlet?

• The electrons move back to the cathode

• The chemical reactions in the battery reverse and recharge the battery

• The electrons react with the lithium ions

• The electrons react with the electrolyte