1)
a)
D = 0.79 g/cm³ m = 85.1 g
D = m / V
0.79 = 85.1 / V
V = 85.1 / 0.79 => 107.72 cm³
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b) D = m / V
0.79 = m / 125
m = 0.79 x 125 => 98.75 g
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hope this helps!
Gee. I'll have to guess at what's "commonly thought".
One thing is the scale. Nobody has an accurate picture of the scale in
his head, because we never see a true-scale drawing. THAT's because
it's almost impossible to draw one on paper.
Example:
Shrink the solar system and everything in it so that the Sun
is the size of a quarter (the 25¢ coin).
Then:
-- The Earth is in orbit around the sun, 8.6 feet from it.
That's close enough that you might think you could find the
shrunken Earth. Unfortunately, it's only 0.009 inch in diameter.
-- The shrunken Jupiter is a 'huge' gas giant almost 0.1 inch in diameter.
It's orbiting the sun, about 45 feet away from it.
-- The shrunken Uranus is another gas giant, about 0.035 inch in diameter.
It's orbiting the sun, about 165 feet away from it.
-- The nearest star outside of the solar system is 441 MILES away !
On the same shrunken scale !
And there's NOTHING between here and there !
I think that's the biggest point to make about the REAL solar system ...
its utter emptiness. With the sun reduced to something you can hold
in your hand, the planets are the size of grains of sand, with hundreds
of feet of nothingness between them.
Same for its mass: The solar system is approximately nothing but a star.
That's it. A star, with some dust and some gas around it, and here and there
in the neighborhood a microscopic pebble or a chip of mineral. But mostly
it's nothing but a star ... if you went around and gathered up all that other
rubbish in the same bag and called it a part of the same solar system, the
sun would still have more than 99% of the total mass, and the bag would
hold less than 1% of it.
Book ... It's getting late, Hillary's fading, and that's all I can think of.
I hope this much is some help.
Answer is: Allena is correct. It is an element because it is only made of chlorine atoms.
A chemical element bonded to an identical chemical element is not a chemical compound since it is made from only one element and not from two different elements. Chlorine is molecule, but not compound.
Rutherford theorized that atoms have their charge concentrated in a very small nucleus.
This was famous Rutherford's Gold Foil Experiment: he bombarded thin foil of gold with positive alpha particles (helium atom particles, consist of two protons and two neutrons).
Rutherford observed the deflection of alpha particles on the photographic film and notice that most of alpha particles passed straight through foil.
That is different from Plum Pudding model, because it shows that most of the atom is empty space.
According to Rutherford model of the atom:
1) Atoms have their charge concentrated in a very small nucleus.
2) Major space in an atom is empty.
3) Atoms nucleus is surrounded by negatively charged particles called electrons.
4) An atom is electrically neutral.
