Test One Flashcards
Pg (1-6)
An argon atom: What does the number 40 represent at the top?
- The mass number
- number of protons and neutrons
How many protons does this atom of argon have?
18
How many neutrons does this atom of argon have?
22
The nucleus of a neon atom has a charge.
What is the charge?
Positive
A neon atom has 10 protons, 10 electrons and 10 neutrons.
Explain why there is no overall charge on a neon atom.
- Equal number of protons and electrons
- the positive cancels out the negative charge
allow
There are two different types of neon atoms.
What are these different types of atoms called?
Isotopes
What are isotopes?
- Atoms with the same number of protons
- But with a different number of neutrons
The sodium atoms emit light.
What would cause light to be emitted from a sodium atom?
Electrons falling to a lower energy level
Describe how the arrangement of the sodium atoms changes as the sodium goes from solid to liquid to gas.
Solid
* atoms closely packed
* atoms in a regular arrangement
Liquid
* atoms are close together
* atoms are not in regular arrangement
Gas
* atoms are well separated
* atoms are not in regular arrangement
Types of sodium lamp
A - 35
B - 50
C - 70
D - 100
E - 150
- 60 × 60
- E = 150 × 3600
- E = 540 000 (J)
Many housing estates are lit by type A sodium lamps.
Suggest two advantages of using type A sodium lamps on housing estates.
- Less energy transferred
- Not as bright
Describe the structure of a DNA molecule.
- 2 strands
- Double Helix
A gene is a small section of DNA on a chromosome.
Complete the sentences.
A gene codes for a particular sequence of _______________.
This sequence makes a specific _______________.
A gene codes for a particular sequence of amino acids
This sequence makes a specific protein
What is meant by the term genome?
All the genetic material (of an organism)
Which important scientific advance was made using knowledge of the human
genome?
Tracing how aboriginal people spread across Australia
