Physics, Chemistry & earth/space

Question 1

What is a physical quantity?

Answer 1

Physical quantities are quantity in physics that can be measured and given a number

Question 2

what is a scalar quantity?

Answer 2

quantity that has size but not direction

Question 3

what is a vector quantity?

Answer 3

is a quantity that has size and direction

Question 4

what is distance?

Answer 4

• Is how far an object travels in total

- Is a scalar quantity measured in meters

Question 5

what is displacement?

Answer 5

• is the straight-line distance between the starting and finishing points
• is a vector quantity, and is also measured in meters

Question 6

what is speed?

Answer 6

How fast something is moving. Uses distance for calculating it. It is a Scalar Quantity

Question 7

what is velocity?

Answer 7

How fast something is moving with a direction. Uses displacement for calculating it. It is a Vector Quantity

Question 8

what is acceleration?

Answer 8

the rate of change of velocity. Is a Vector value. Given the unit m s-2

Question 9

how do you identify acceleration?

Answer 9

• If an object is changing speed or direction then it is accelerating
• Also, objects with unbalanced forces applied are accelerating

Question 10

what is newtons 1st law?

Answer 10

Law of inertia - An object at rest tends to remain at rest; an object in motion tends to remain in motion at constant speed along a straight-line path

Question 11

what is newtons 2nd law?

Answer 11

When a force acts on an object, the object will accelerate. The acceleration is proportional to the net force and inversely proportional to the mass

Question 12

what is newtons 3rd law?

Answer 12

Law of action/reaction - Whenever one object exerts a force on a second object, the second object exerts an equal and opposite reaction on the first

Question 13

what is the law of conservation of energy?

Answer 13

Energy cannot be created or destroyed, only transferred or transformed

Question 14

what is the relationship between distance from sun and temperature?

Answer 14

as the distance from the sun increases the average temperature decreases

Question 15

what is the difference in temperature of objects with atmosphere compared to those without?

Answer 15

the objects with an atmosphere have a hotter average temperature than the objects without

Question 16

what is the relationship between atmosphere and planet surface temperature?

Answer 16

• planet temperature increases exponentially as it gets closer to the heat source
• a greater volume of atmosphere traps in heat and increases temperature
• higher carbon dioxide levels in atmosphere make planets hotter

Question 17

what is the impact of carbon dioxide on a planet’s temperature?

Answer 17

• Carbon dioxide has led to an enhanced greenhouse effect, altering temperature and rainfall patterns significantly.
• Rising carbon dioxide concentrations are already causing the planet to heat up

Question 18

what is the carbon cycle?

Answer 18

The carbon cycle describes the process where carbon atoms continually travel from the atmosphere to the Earth and then back to the atmosphere

Question 19

how does carbon move through the cycle?

Answer 19

Carbon can cycle through the land, oceans and atmosphere over both the short and long term

Question 20

what is the geological carbon cycle?

Answer 20

The geological carbon cycle is a long- term cycle that occurs over hundreds to millions of years and has resulted in the bulk of carbon being locked in rocks or in sediments as fossil fuels

Question 21

what is the biological/physical carbon cycle?

Answer 21

The biological/physical carbon cycle is a short-term cycle that occurs over days, weeks, months and years and involves the cycling of carbon through photosynthesis and cellular respiration

Question 22

what are some key participants in the carbon cycle?

Answer 22

• Fire plays an important role in transferring carbon dioxide from the land to the atmosphere. Fires consume biomass and organic matter, producing carbon dioxide as well as methane, carbon monoxide and smoke
• Carbon is stored over the long term in the trunks and branches of trees. It is also temporarily stored in the bodies of other organisms, such as herbivores and carnivores.
• When these organisms die, carbon is returned to the atmosphere as carbon dioxide by decomposers

Question 23

what are carbon sinks?

Answer 23

A forest, ocean, or other natural environment with the ability to absorb carbon dioxide from the atmosphere

Question 24

what are the 2 main carbon sinks?

Answer 24

• Forests take in carbon dioxide, so they are a very significant carbon sink. However, the ability of forests to absorb carbon has been reduced as a result of the large scale clearing of forests
• The ocean is another important carbon sink, absorbing atmospheric carbon dioxide and consequently becoming more acidic

Question 25

what can carbon be stored in?

Answer 25

> decomposed organic matter, such as coal, natural gas, petroleum and shale oil
rocks, such as limestone, marble, dolomite, chalk and other carbonates
organic matter in the soil
dissolved carbon dioxide in the oceans and other waters
the shells of marine organisms and some terrestrial organisms

Question 26

what is the human impact on the carbon cycle?

Answer 26

> we have reduced the total mass of fished species
freshwater ecosystems have been altered through the building of dams and hydroelectric power production, resulting in changed river flows
agriculture and farming have converted more than half the world’s many grasslands for human use
Human activity has diverted or prevented 20–30% of the flow of energy that is fixed by natural ecosystems. This is due to:
maintaining crops
establishing urban areas
grazing livestock
habitat degradation

Question 27

what is the collision theory?

Answer 27

A theory that states the particles involved in a chemical reaction must collide in order to react

Question 28

what is the structure of atoms in terms of electron shells?

Answer 28

• Periodic table lists all the known elements in order of increasing atomic number
• Elements are organized into rows and columns
• Rows are called periods
• Columns are called groups

Question 29

what are periods?

Answer 29

• The period number is equal to the number of electron shells
• For example: Li, Be, B, C, N, O, F, Ne are elements in ‘Period 2’ – they have 2 electron shells

Question 30

what are groups?

Answer 30

• vertical columns numbered 1 to 18.
• Group number: the last digit reflects the number of valence electrons
• valence electrons: electrons located in the outer most electron shell

Question 31

what are valence electrons?

Answer 31

An electron located in the outermost electron shell

• GROUP 1: 1e-
• GROUP 2: 2e- SKIP A FEW!!
• GROUP 13: 3e-
• GROUP 14: 4e-
• GROUP 15: 5e-
• GROUP 16: 6e-
• GROUP 17: 7e-
• GROUP 18: 8e- FULL SHELL!!! Noble gases

Question 32

what are ion charges?

Answer 32

• ion charges can be calculated from the group number
• How many valence electrons does each atom need to lose/gain to obtain a full outer shell?
• GROUP 1: 1e- LOSE 1e-, 1+ charge
• GROUP 2: 2e- LOSE 2e-, 2+ charge
• GROUP 13: 3e- LOSE 3e-, 3+ charge
• GROUP 14: 4e- SKIP!! electrons are shared
• GROUP 15: 5e- GAIN 3e-, 3- charge
• GROUP 16: 6e- GAIN 2e-, 2- charge
• GROUP 17: 7e- GAIN 1e-, 1- charge
• GROUP 18: 8e ALREADY FULL!!

Question 33

what are the fist 20 elements on the periodic table?

Answer 33

Hydrogen (H)
Helium (He)
Lithium (Li)
Beryllium (Be)
Boron (B)
Carbon (C)
Nitrogen (N)
Oxygen (O)
Fluorine (F)
Neon (Ne)
Sodium (Na)
Magnesium (Mg)
Aluminum (Al)
Silicon (Si)
Phosphorus (P)
Sulfur (S)
Chlorine (Cl)
Argon (Ar)
Potassium (K)
Calcium (Ca)