Physics, Chemistry & earth/space Flashcards

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1
Q

What is a physical quantity?

A

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

2
Q

what is a scalar quantity?

A

quantity that has size but not direction

3
Q

what is a vector quantity?

A

is a quantity that has size and direction

4
Q

what is distance?

A
• Is how far an object travels in total

- Is a scalar quantity measured in meters

5
Q

what is displacement?

A
• is the straight-line distance between the starting and finishing points
• is a vector quantity, and is also measured in meters
6
Q

what is speed?

A

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

7
Q

what is velocity?

A

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

8
Q

what is acceleration?

A

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

9
Q

how do you identify acceleration?

A
• If an object is changing speed or direction then it is accelerating
• Also, objects with unbalanced forces applied are accelerating
10
Q

what is newtons 1st law?

A

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

11
Q

what is newtons 2nd law?

A

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

12
Q

what is newtons 3rd law?

A

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

13
Q

what is the law of conservation of energy?

A

Energy cannot be created or destroyed, only transferred or transformed

14
Q

what is the relationship between distance from sun and temperature?

A

as the distance from the sun increases the average temperature decreases

15
Q

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

A

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

16
Q

what is the relationship between atmosphere and planet surface temperature?

A
• 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
17
Q

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

A
• 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
18
Q

what is the carbon cycle?

A

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

19
Q

how does carbon move through the cycle?

A

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

20
Q

what is the geological carbon cycle?

A

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

21
Q

what is the biological/physical carbon cycle?

A

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

22
Q

what are some key participants in the carbon cycle?

A
• 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
23
Q

what are carbon sinks?

A

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

24
Q

what are the 2 main carbon sinks?

A
• 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
25
Q

what can carbon be stored in?

A

> 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

26
Q

what is the human impact on the carbon cycle?

A

> 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

27
Q

what is the collision theory?

A

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

28
Q

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

A
• 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
29
Q

what are periods?

A
• 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
30
Q

what are groups?

A
• 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
31
Q

what are valence electrons?

A

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
32
Q

what are ion charges?

A
• 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!!
33
Q

what are the fist 20 elements on the periodic table?

A
```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)```