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Fall13 Science Syd
8th grade Science
Question | Answer |
---|---|
a particle that has a positive charge | proton |
The fact that an atom is neutral is most closely related to | the number of protons ad electrons the atom contains |
Electrons involved in bonding between atoms are | valence electrons |
What is the greatest number of valence elections an atom can have that we've learned about this year? | 3 |
From an elements location in the periodic table you can predict | its properties |
The elements in a column of the periodic table | are in the same group |
The elements in a group, or family, of the periodic table have the same | physical properties |
Across a period of elements in the periodic table, the number of valence electrons | increases from left to right |
Which process changes matter into one or more new substances | chemical change |
Water vapor in the air turns to liquid water in the form of rain. This is an example of a | physical change |
every chemical reaction involves a change in | energy |
in the following equation what does the number 4 in 4 H2O tell you? 2NH4NO3>2N2+4H2) | The reaction produces 4 water molecules |
The substance listed on the LEFT side of a chemical equation are the | Reactants |
in chemical reactions, what does the principle of conservation of mass mean | matter is not created or destroyed |
Which of the following is a balanced chemical equation | 2Fe2O3+3C>4Fe+3CO2 |
In an equation, numbers often appear in front of a chemical formula. These number (Coefficient) tell you the | number of atoms in each molecule in the reaction |
A bottle of hydrogen peroxide that eventually turns into a bottle of water and oxygen gas is an example of a | decomposition |
The chemical reaction between copper oxide and carbon that produces copper and carbon dioxide (CuO + C > Cu + CO2) is an example of | replacement |
The outside of the space shuttle is protected from extremely high heat during reentry by an outer covering of | ceramic tiles |
Reactions involving the particles in the nucleus of an atom are called | chemical reactions |
An object is in motion only if it changes potion relative to | a reference point |
What is the formula for the speed of an object | speed = distance/time |
the rate at which the velocity of an object changes is its | acceleration |
what causes an object to accelerate | a force exerted on it |
newtons first law of motion states that an object at rest will | remain at rest unless a force is exerted on it |
the transfer of energy by electromagnetic wave is called | radiation |
Energy that is transferred by electromagnetic waves in the universe is called | electromagnetic radiation |
All electromagnetic waves have the same | speed |
Which electromagnetic waves have the longest wavelengths and lowest frequencies | radio waves |
visible light has a higher frequency than | infrared rays |
the range of electromagnetic waves placed in a certain order is called the | electromagnetic spectrum |
The electromagnetic waves with the highest frequencies are called | gamma rays |
visible light can be separated into the various colors of the visible spectrum to form | rainbow |
both reflecting and refracting telescopes are designed to | collect and focus visible light |
reflecting telescopes differ from refracting telescopes in having | no eye piece lens |
The hubble Space Telescope | collects visible light from above Earths atmosphere |
Spectrographs help astronomers determine the | temperature of a star |
the chemical composition of a star can be determined using a | spectrograph |
a light year is | the distance light travels in a year |
parallax is a method used to determine a stars | distance from earth |
what color are the hottest stars | blue-white |
The hertz sprung russell diagram shows that main dquence stars | increase in brightness as they increase in temperature |
all stars begin their lives as parts of | protostars |
the lifetime of a star depends on its | mass |
when stars begin to run out of fuel they first become | red giants or supergiants |
black holes form from the remains of stars that | were more than 40 times the mass of the sun |
when a white dwarf stops glowing it becomes a | black dwarf |
how are the elliptical galaxies and spiral galaxies different | elliptical galaxies have little gas and dust |
the theory that astronomers have developed to describe the beginning of the universe is called the | big bang theory |
one piece of evidence that supports the big bang theory is the observation that most galaxies are moving | away from one another |
according to the big bang theory, the universe began about | 10-15 billion years ago |
the solar system form from | nebula |
when the solar system formed the spheres that lost most of their gases became the | inner planets |
day and night are caused by | earth's rotation on its axis |
one complete revolution of earth around the sun takes about | one year |
earth has season because | earth's axis is tilted as it moves around the sun |
when the north end of earth's axis is tilted toward the sun, North America will experience | more direct rays and longer days (summer) |
an Equinox occurs when | Earth's axis is tilted neither toward nor away from the sun |
because the moon rotates once for revolution around Earth | you never see the far side of the moon |
the pass of the moon you see depends on | how much of the moon's surface is lit by the sun |
from new moon phase to full moon phase you see | an increasing amount of the lighted side of the moon |
for a solar eclipse to occur | the moon must be directly between Earth and the sun |
during what phase can a lunar eclipse occur | full |
you are less likely to see a solar eclipse than a lunar eclipse because | you must be in the moons shadow to see a solar eclipse |
not every place on Earth has two regular Tides every day because | the shapes of bays, inlets, and the ocean floor can affect the flow of water |
most places on Earth experience | two high tides and two low tides about every 12.5 hours |
a spring tide can only at sketch Spring Tide | new moon (the best/highest) |
How large is the moon's diameter compared to Earth? | about one fourth the diameter of Earth |
Scientist think the moon was formed when | a large object struck Earth, and material from both bodies combined and was thrown into orbit |
Galileo thought that the dark, flat parts of the noon's surface were | oceans |
The moon includes all of the following features EXCEPT | oceans |
All of the following conditions are needed for life on Earth EXCEPT | one natural satellite that orbits the planet |
Which of the following is a reason scientists think Mars may have once had life? | Mars has surface features that could have been made by flowing water |
one complete Revolution of Earth around the sun takes about | one year |
What is the oxidation number for Lithium | +1 |
An oxidation number of -2 would represent what element | Sulfur |
The ability to Shine | Luster |
The Ability to bend without breaking | malleable |
The ability to transfer | conduction |
the ability to break easily | brittle |
you can show the motion of an object on a line graph in which you plot distance against | Time |
A train that travels 100 kilometers in 4 hours is traveling at what average speed | 25 km/h |
An example of qualitative observations is | Green |