Planet Earth Midterm

Question 1

What is the scientific method?

Answer 1

A systematic process for studying the natural world through observation, hypothesis, experimentation, and conclusions.

Question 2

What is a hypothesis?

Answer 2

A testable and educated guess or explanation

Question 3

What is a scientific theory?

Answer 3

A well-supported explanation of natural phenomena based on evidence.

Question 4

What is a scientific law?

Answer 4

A statement describing consistent natural phenomena, often with a mathematical expression.

Question 5

What is the Big Bang theory?

Answer 5

The universe started from an extremely hot, dense point ~13.8 billion years ago and has been expanding since.

Question 6

What is the multiverse theory?

Answer 6

The idea that our universe is one of many universes, possibly with different physical laws.

Question 7

How did the solar system form?

Answer 7

From a collapsing cloud of gas and dust (solar nebula) about 4.6 billion years ago.

Question 8

How did Earth form?

Answer 8

Through the accretion of dust and rock from the solar nebula.

Question 9

What are the main layers of Earth?

Answer 9

Core, mantle, and crust.

Question 10

What shape is Earth?

Answer 10

An oblate spheroid (flattened at poles, bulging at equator).

Question 11

How old is Earth?

Answer 11

About 4.54 billion years.

Question 12

What are stromatolites, and why are they important?

Answer 12

Structures formed by cyanobacteria; they released oxygen into the atmosphere.

Question 13

What happened during the Ediacaran period?

Answer 13

The first large, complex life forms appeared (~635–541 mya).

Question 14

What is the Cambrian Explosion?

Answer 14

A rapid diversification of life ~541 million years ago.

Question 15

What happened 65 million years ago?

Answer 15

A mass extinction, likely caused by an asteroid, wiped out the dinosaurs.

Question 16

What are the 3 subatomic particles?

Answer 16

Protons, neutrons, and electrons.

Question 17

Where are protons and neutrons found?

Answer 17

In the nucleus.

Question 18

What is a molecule?

Answer 18

A group of atoms bonded together.

Question 19

What is an ionic bond?

Answer 19

A bond formed by the transfer of electrons.

Question 20

What is a covalent bond?

Answer 20

A bond formed by sharing electrons.

Question 21

What is a metallic bond?

Answer 21

A bond where electrons move freely among metal atoms.

Question 22

What is a mineral?

Answer 22

A naturally occurring, inorganic solid with a definite chemical composition.

Question 23

What is a rock?

Answer 23

A solid mixture of minerals.

Question 24

What are the 3 types of rocks?

Answer 24

Igneous, metamorphic, and sedimentary.

Question 25

What is the rock cycle?

Answer 25

The ongoing process of rock transformation through melting, cooling, erosion, and pressure.

Question 26

Igneous Rocks

Answer 26

rocks that come from fire, molten materials, lava, magma

Question 27

Sedimentary Rocks

Answer 27

rocks from sediments, sand compacted for millions of years becomes rock: sandstone limestone

Question 28

Metamorphic Rocks

Answer 28

rocks that the chemical composition changes ex) marble

Question 29

What are tectonic plates?

Answer 29

Large sections of Earth's crust that float on the mantle.

Question 30

Protons

Answer 30

subatomic particle with a defined mass of 1 and a charge of +1

Question 31

Neutrons

Answer 31

subatomic particle that has no electric charge

Question 32

Electrons

Answer 32

subatomic particle with a negative electric charge

Question 33

Who proposed continental drift?

Answer 33

Alfred Wegener.

Question 34

What are the 3 types of plate boundaries?

Answer 34

Convergent, divergent, and transform.

Question 35

Convergent boundaries

Answer 35

plates come together

Question 36

Divergent boundaires

Answer 36

plates move apart in opposite directions

Question 37

Transform boundaries

Answer 37

plates rub against one another, brushing past each other

Question 38

How do tectonic plates form mountains and oceans?

Answer 38

Through collisions (mountains) and separations (rifts/oceans).

Question 39

What is a volcano?

Answer 39

An opening where magma, gases, and ash escape from Earth’s crust.

Question 40

What are the main parts of a volcano?

Answer 40

Magma chamber, conduit (chimney), and crater.

Question 41

What is pyroclastic flow?

Answer 41

A fast, hot flow of gas and volcanic debris.

Question 42

What are the two types of lava?

Answer 42

Pahoehoe (smooth) and aa (rough/jagged).

Question 43

facts

Answer 43

Observations about the world that are consistently true.

Question 44

Experiments:

Answer 44

Controlled methods of testing a hypothesis.

Question 45

Theories

Answer 45

Well-substantiated explanations based on evidence and experimentation.

Question 46

Laws

Answer 46

Descriptions of natural phenomena that hold true under specific conditions, often expressed mathematically (e.g. Newton’s laws).

Question 47

Shape and Size of Earth

Answer 47

Oblate spheroid (slightly flattened at the poles and bulging at the equator); about 12,742 km (7,918 miles) in diameter.

Question 48

Stromatolites and Atmospheric Oxygen

Answer 48

Stromatolites (formed by cyanobacteria) began photosynthesizing around 3.5 billion years ago, releasing oxygen and transforming Earth’s atmosphere (Great Oxygenation Event).

Question 49

Ediacaran Period

Answer 49

Saw the emergence of the first large, complex multicellular life forms.

Question 50

Structure of Atoms

Answer 50

Nucleus (protons + neutrons) in the center, with electrons in surrounding energy levels (shells).

Question 51

Molecules

Answer 51

A group of two or more atoms chemically bonded together.