Atomic Structure
Who carried out the famous gold foil experiment?
Ernest Rutherford
Which group contains the noble gases?
Group 0
Unlike charges ________.
Attract
What instrument measures electric current?
Ammeter
True or False: Metals are good conductors of electricity.
True
What is the centre of an atom called?
Nucleus
Which group contains the halogens?
Group VII
Like charges ________.
Repel
What is the SI unit of electric current?
Ampere (A)
True or False: Objects with the same charge attract each other.
False
Which particle has a negative charge?
Electron
Elements in the same group have the same number of what?
Outermost (valence) electrons
What instrument tells whether an object is positively or negatively charged?
Coulombmeter
What instrument measures voltage?
Voltmeter
Fill in the blank: Negatively charged particles are called __________
Electrons
Which particle has no charge?
Neutron
Name one alkali metal.
Lithium, Sodium or Potassium
What happens when you rub a balloon on your hair?
Electrons move, causing static electricity.
In which type of circuit is the current the same everywhere?
Series circuit
Fill in the blank: Components connected in one continuous loop form a ________ circuit.
Series
Which particle determines the atomic number?
Proton
Why are alkali metals stored in oil?
To prevent them from reacting with air and water.
What is grounding?
Connecting a charged object to the Earth to remove excess charge
Which circuit has more than one path?
Parallel circuit
Fill in the blank: A circuit with several branches is called a ________ circuit.
Parallel
What did Rutherford discover from the gold foil experiment?
Most of the atom is empty space
Which group is the least reactive?
Noble gases (Group 0)
What natural event is caused by a rapid discharge of electricity?
Lightning
What is resistance?
Opposition to the flow of electric current.
Why does current decrease when more bulbs are added to a series circuit?
The total resistance increases.
How many protons does a sodium atom have?
11
Why do elements in the same group have similar chemical properties?
They have the same number of outermost electrons.
Why does hair stand up near a Van de Graaff generator?
Each hair gets the same charge and repels the others.
Which resistor can change its resistance?
Variable resistor (Rheostat)
What happens to the voltage across components in a parallel circuit?
It stays the same across each branch.
Why do electrons stay around the nucleus?
They are attracted to the positively charged nucleus.
What is the atomic number?
The number of protons.
Name one good conductor of electricity.
Copper (or any metal)
Why are bulbs brighter in a parallel circuit than in a series circuit?
Each bulb receives the full voltage.
Describe how a charged conductor can be discharged.
By connecting it to the Earth (grounding).
How many protons, electrons, and neutrons are in sodium (Na-23)?
Protons = 11, Electrons = 11, Neutrons = 12
Why are noble gases called "noble"?
They rarely react because their outer electron shell is full.
Explain the difference between a conductor and an insulator.
Conductors allow electricity to flow easily; insulators do not.
Describe how current flows in a parallel circuit.
It splits into different branches and rejoins later.
A sodium atom has an atomic number of 11 and a mass number of 23. How many protons, electrons and neutrons does it have?
Protons = 11, Electrons = 11, Neutrons = 12