Conduction in Liquids and Gases

Arc

luminous charge of electricity through gas

Electrolysis

use of an electric current to separate chemical compounds or metals

Electron impact

collision that occurs when one electron strikes another electron or object

Electroplating

act of depositing electrons from one type of metal onto the other

Ion

charged atom

If an atom gains electrons it will become

negatively charged

If an atom loses electrons it will become

positively charged

Ionization potential

amount of voltage or potential that must be applied to cause ionization of a gas

Metallic salt

chemical compound that is generally in a crystal state and exhibits the properties of a metal

X rays

beams of high energy protons

Magnesium is a

metal

Chlorine is a

gas

Magnesium has how many valence electrons

two

Chlorine has how many valence electrons

seven

When chlorine and magnesium combine in the presence of heat what is formed

magnesium chloride

Magnesium chloride is what type of compound

a salt

What is added to water to make it conductive

some salt

Compounds that can dissociate in solution in order to conduct electric current are

called electrolytes

Only salts can be electrolytes: T/F

False (various acids and bases can also be electrolytic)

Electrolyte commonly used in lead-acid batteries

sulfuric acid

Sulfuric acid formula

H2SO4

In its pure form is sulfuric acid is an electrolyte?

No it is not

What must be done to make sulfuric acid electrolytic

water must be added

What does H2SO4 dissociate into in water

H2+ and SO42-

What holds the sulfate ion together

the 2 electrons

SO42- is called

sulfate ion

Copper Sulfate in its natural state

blue crystals

When CuSO4 dissociates what ions are formed

Cu2+ and SO42-

Cu2+ is a

cupric ion

Copper sulfate is used in what process

the electroplating process

Cuprous Cyanide formula

CuCN

What ions are formed in solution from CuCN

Cu+, CN-

Cu+ is called

cuprous ion

CuCN is used for

plating copper onto iron

What must be present in the electrolyte solution for electroplating

ions of the metal to be plated

Electroplating: metal ions always carry what charge

positive

Electroplating: object to be plated is connected to

the negative terminal (cathode)

Cathode

negative terminal of a power source

What happens at the cathode

electrons enter the solution

What type of power source is used for electroplating

direct current

The positive terminal is made from

the same metal that will form the coating

Anode

positive terminal of a power source

What happens at the anode

the electrons leave the circuit

Common use for electroplating

production of pure metals

Process commonly used to extract aluminium from Al2O3

is electrolysis

Air is an insulator or conductor

insulator

How can the resistance of air be overcome

with the right amount of voltage potential

What happens between 2 electrodes separated by air once a high enough potential is reached

an arc forms

Once an arc is established, what limits the current in this circuit

the impedence

What happens to the air as an arc between 2 electrodes is established

it becomes ionized and the ionized gas will maintain conduction

One factor that determines voltage required to establish an arc

distance between the 2 electrodes

Factors that determine amount of voltage required to cause ionization in a gas-filled envelope/tube

atmospheric pressure and type of gas in the surrounding atmosphere

Increased pressure means the ionization potential increases or decreases

ionization potential increases

Gas-filled tubes/envelopes operate with lower or higher than normal atmospheric pressure in the tube

lower than normal

Most important factor in ionization of a gas

is electron impact

What determines the density inside a gas filled tube

the pressure

What happens if the pressure is high in a gas tube

the gas will be too dense for an electron to travel through and it will bounce from one molecule to another

Applications of conduction in gases

production of light

X Rays

Cathode Ray tubes

What happens if an electron strikes a gas molecule that is too low energy to release other electrons

the molecule will release excess energy in the form of light

The colour of the light released is a

characteristic of the type of gas

X rays pass through __ better than _ metal

thin metal better than thick

X rays pass through __ better than _

flesh better than bones

JJ Thompson found that a beam of negative particles could be bent by

magnetic fields

Cathode Ray tubes were used in

TVs

computer displays

oscilliscopes

Ionization in nature

northern lights

St Elmo’s fire

Factors that determine the speed an electron reaches in a gas tube

applied voltage

distance travelled before hitting another electronS

Speed of an electron in a gas tube is ____ to applied voltage and distance travelled

is proportional to applied voltage and distance travelled