Science Terms H-M

Question 1

heliocentric model

Answer 1

the model of the solar system that places the Sun at the center with the planets orbiting around it

Question 2

heterogeneous

Answer 2

a mixture that is not uniform in composition

Question 3

homogeneous

Answer 3

a mixture in which the components are uniformly distributed

Question 4

hydrate

Answer 4

a crystal of a molecule that also contains water in the crystal structure. If the water evaporates, the crystal becomes anhydrous.

Question 5

hydrology

Answer 5

the study of the Earth’s water and water systems

Question 6

hypothesis

Answer 6

a step in the scientific method where a prediction is made about the end result of an experiment. A hypothesis is generally based on research of related data.

Question 7

igneous rock

Answer 7

a rock formed through the cooling of magma

Question 8

image distance

Answer 8

the distance from an image to a mirror or lens

Question 9

inertia

Answer 9

the tendency of an object to follow Newton’s First Law, the law of inertia. That is the tendency of an object to remain at rest or in motion with constant velocity unless acted on by a force.

Question 10

inorganic

Answer 10

a material that is neither plant nor animal in origin

Question 11

intensity

Answer 11

the power per unit area of a wave; measured in Watts/m2

Question 12

ion

Answer 12

an atom that has either lost electrons to become a positively charged cation, or has gained electrons to become a negatively charged anion

Question 13

isomers

Answer 13

substances that have the same molecular formula (same number of elements) in different arrangements

Question 14

isotopes

Answer 14

atoms of the same element, with different numbers of neutrons, and hence a different atomic mass

Question 15

Jovian planet

Answer 15

one of the outer planets of the solar system that have characteristics similar to that of Jupiter. They are also called gas planets. They are large, have high mass, have many moons, may have rings, are far from the Sun and each other, have thick atmospheres, are gaseous and have low density, have a composition similar to that of the Sun, have short rotation rates, and have long revolution periods around the Sun. The Jovian planets are Jupiter, Saturn, Uranus, and Neptune.

Question 16

kinetic energy

Answer 16

the energy due to an object’s motion or velocity

Question 17

land breeze

Answer 17

the breeze that develops on the shoreline due to unequal heating of the air above the land and ocean. Land breeze occurs at night when the air above the land is cooler and the air above the ocean is warmer. The breeze blows from the land to the sea.

Question 18

latitude

Answer 18

the coordinate used to measure positions on the Earth north or south of the Earth’s equator. Latitude is measured in degrees, minutes, and seconds. Zero degrees latitude is the Earth’s equator.

Question 19

longitude

Answer 19

the coordinate used to measure positions on the Earth east or west of the prime meridian, which goes through Greenwich, England. Longitude is measured in degrees, minutes, and seconds.

Question 20

longitudinal wave

Answer 20

a wave that has the direction of motion of the particles in the medium parallel to the direction of motion of the wave. Sound is an example of a longitudinal wave.

Question 21

mass

Answer 21

the amount of matter in an object; also a measure of the amount of inertia of an object. Common units are kilograms (kg).

Question 22

meander

Answer 22

a broad curve in a river

Question 23

meiosis

Answer 23

a process of cellular reproduction where the daughter cells have half the amount of chromosomes. This is used for purposes of sexual reproduction to produce sex cells that will be able to form an offspring with a complete set of chromosomes with different DNA than the parents.

Question 24

meniscus

Answer 24

the curved surface of a liquid in a container, caused by surface tension

Question 25

metamorphic rock

Answer 25

a rock whose crystal structure has been changed through heat and/or pressure

Question 26

meteorology

Answer 26

the study of the Earth’s atmosphere and weather

Question 27

mid-oceanic

Answer 27

ridge a region under the ocean where new crust is being created, and the plates on either side of the ridge are moving apart

Question 28

mineral

Answer 28

a naturally occurring element or compound found in the Earth’s crust

Question 29

mitochondria

Answer 29

an organelle that produces ATP

Question 30

mitosis

Answer 30

a process in which cells produce genetically identical offspring

Question 31

mixture

Answer 31

a physical combination of different substances

Question 32

mole

Answer 32

the amount of substance that contains as many particles as there are atoms in 12 grams of the carbon 12 isotope (6.022 x 1023 particles)

Question 33

molecular mass

Answer 33

the sum of the atomic masses in a molecule

Question 34

molecule

Answer 34

a substance formed by a chemical bond between two or more atoms