The Material World

Question 1

What is electrical conductivity?

Answer 1

Electrical conductivity of a solution is a measure of its ability to allow an electric current to flow through.

Question 2

What is electric dissolution?

Answer 2

Electric dissolution is the separation of a dissolved compound into two ions of opposite charges. (Positive-negative)

Question 3

What is an electrolyte?

Answer 3

An electrolyte is a substance that when dissolved in water, allows an electric current to flow through the solution.

Question 4

What are the three types of electrolytes?

Answer 4

Acids, bases and salts.

Question 5

What is the concept of an ion?

Answer 5

An atom that has become electrically charged by losing or gaining one or more electrons

Question 6

Formation of an ionic bond?

Answer 6

An ionic bond is the result of a transfer of one or more electrons from one atom to another atom ( metal to nonmetal)

Question 7

What Is combustion?

Answer 7

Combustion is a form of oxidation that releases a large amount of energy.

Question 8

What are examples of combustion?

Answer 8

Burning wood, rusting iron and cellular respiration.

Question 9

Explain rapid combustion.

Answer 9

Rapid combustion is when in a short period of time it releases a great deal of energy mostly in the form of heat and light.

Question 10

Explain the fire triangle.

Answer 10

1. In oxidizing agent or oxidant is a substance that can cause a fuel to react.
2. A fuel is a substance that releases a large amount of energy by reacting with an oxidizing agent wood and propane are excellent fuels
3. The ignition temperature is the minimum temperature at which the energy present is sufficient to start combustion

Question 11

What is in aqueous solution?

Answer 11

It is a solution in which the solvent is water

Question 12

What is a salt?

Answer 12

salt is the substance produced by the chemical bonding of a metallic ion and a nonmetallic ion.

Question 13

Describe the pH scale

Answer 13

The pH scale ranges from 0 to 14. It indicates how acid or basic a solution is.

Question 14

What is the classification of the pH scale?

Answer 14

If the pH is less than seven the solution is acidic. If the pH equals seven the solution is neutral. If the pH is greater than seven the solution is basic.

Question 15

What is an acid base neutralization reaction?

Answer 15

Acid-base neutralization is a chemical change involving the reaction of an acid with a base,producing a salt and water.

Question 16

Example of an acid-base neutralization reaction

Answer 16

Na+(aq) + CI-(aq) + H2O(l)

   Salt                Water

Question 17

Describe the law of conservation of mass

Answer 17

The law of conservation of mass states that the total mass of reactants is always equal to the total mass of products.

Question 18

Describe the Rutherford bore atomic model

Answer 18

The Rutherford bore atomic model is a representation of the Adam as a very small nucleus made up of positively charged protons, surrounded by negatively charged electrons moving in defined orbits.

Question 19

What is the electrical charge of a proton, neutron and electron?

Answer 19

Proton = positive charge
neutron = no charge
electron = negative charge
Different particles have different charges.

Question 20

What happens with two objects with similar electrical charges?

Answer 20

They repel each other.

Question 21

What happens with two objects with opposite electrical charges?

Answer 21

They will attract each other.

Question 22

What is static electricity?

Answer 22

Static electricity is the transfer of electrons from one body to another.

Question 23

What is the relationship between voltage current intensity and resistance in an electrical circuit?

Answer 23

The relationship between voltage and current intensity and resistance in an electrical circuit is called ohms law. All materials are made up from atoms, and all atoms consist of protons, neutrons and electrons.

Question 24

Describe the difference between alternating and direct current.

Answer 24

The difference between direct current and alternating current is that direct-current goes in one direction negative to positive. And alternating current goes in any direction.

Question 25

Describe the series circuit.

Answer 25

I’ll components connected in the loop. If one component doesn’t function, entire circuit won’t work

Question 26

Describe the parallel circuit.

Answer 26

The parallel circuit contains at least one branch/ junction where electrons can split into a different path.

Question 27

What circuit is the ammeter always connected to?

Answer 27

The series circuit

Question 28

What circuit is the voltmeter always connected to?

Answer 28

The meter is always connected in parallel.

Question 29

What is a magnet?

Answer 29

A magnet is an object that can attract other objects containing iron cobalt or nickel.

Question 30

What is magnetism?

Answer 30

Magnetism describes all the phenomena caused by magnets.

Question 31

Do Opposite poles attract?

Answer 31

Yes they do.

Question 32

What is a magnetic field?

Answer 32

A magnetic field is the area of space in which the magnetic force of a magnet can act on another magnet.

Question 33

Do similar poles repel?

Answer 33

Yes they do

Question 34

What is the behavior of a compass in the magnetic field of a magnet?

Answer 34

The compass is equipped with a freely moving magnetize needle, which rapidly locate the magnetic north pole.

Question 35

Explain the law of conservation of energy.

Answer 35

The law of conservation of energy states that the energy can be neither created nor destroyed; it can only be transferred or transformed.

Question 36

What is energy efficiency?

Answer 36

Energy efficiency is the percentage of energy consumed by a machine or system that was transformed into useful energy.

Question 37

Define energy efficiency of a device or system.

Answer 37

The portion of energy consumed that is transformed into effective work.