science studying
stars in the north sky appear to rotate around a single point known as
The north star
how long does it take earth to rotate around its own axis?
24 hours
how long does it take for the earth to complete one full revolution/orbit around the sun?
365 days
the earths axis is tilted at an angle of how many degrees?
23.5 degrees
how long does it take the moon to rotate around its own axis? How long does it take for the moon to complete one full revolution/orbit around the sun?
27.3 days for both
Moon is between the sun and earth-is this lunar or solar eclipse
solar eclipse
Earth is between the sun and moon- is this lunar or solar eclipse?
lunar eclipse
what is the name of the unit of measurement used for distances between planets?
astronomical units
what is a galaxy?
collection of billions of stars held together by gravity
what is the universe?
everything that exists, including celestial objects, matter and empty space surrounding them
what periodic table elements are mainly found in the sun?
hydrogen and helium
what is the difference between a compound and an element?
compound: made of two or more elements to form a molecule
element: made of one kind of particle called an atom
A molecule of methane is composed of one atom of carbon and four atoms of hydrogen. What is the formula for methane?
CH4
in the nucleus of most atoms, we find, which two subatomic particles?
protons and neutrons
A certain atom contains 17 protons, 20 neutrons, and 17 electrons. the atomic mass of this element is:
protons+neutrons=atomic mass=17+20=37
what are the indications that a chemical change has occurred?
change in tempurature, change in colour, gas/odour, a solid precipate
when a solid becomes a gas, it is referred to as:
Sublimation
A sample has a mass of 2.90 G and a volume of 0.15 ML. find its density
given: mass=m=2.90g
unknown: density=d=?gmL
equation: ?=d=m%v
solve:?=19.3g/mL
answer: therefor, the density of the sample is 19.3g/mL
what device is used to measure Electric potential difference? How is it connected in a circuit?
voltmeter: One wire connected to one side of an electrical load, and one wire connected to the other side of the electrical load
what is the difference between parallel and series circuit?
series: is one possible path for electrons to travel to and from a battery through conducting wires. parallel: is more than one path for electrons to travel to and from a battery through conducting wires
draw a diagram that shows how the charges move from fur to ebonite what type of charging are you using?
charging by friction
electric load=
motor
voltage=
potential difference
current=
rate of flow of electrons
resistance=
the ability of a material to oppose the flow of electric current
ohm=
unit for resistance
ampere=
unit for "i"