Answer:
The mass of silicon in kilograms in Earth's crust is
.
Explanation:
Mass of Earth =
(1 ton= 2000 lb)
(1 lb =453.6 g)
1 ton = 2000 × 453.6 g =907,200 g
Mass of Earth =
Percentage of earth crust = 0.50%
Mass of earth crust = M


Percentage of the silicon in Earth's crust = 27.2 %
Mass of silicon in in Earth's crust = m



1000 g = 1 kg
The mass of silicon in kilograms in Earth's crust is
.
<span>The magnetic field of the Earth serves a useful purpose in deflecting Solar radiation. Without the magnetic field there is much more charged-particle radiation striking the surface. The auroras would occur everywhere instead of at the magnetic poles. Compass needles wouldn't work, and then they would flip direction.. The magnetic field IS DECREASING and could go to zero and reverse sometime in the next few tens-of-thousands of years.</span>
<span>Answer: option (4) the same magnitude and the opposite sign.
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Justification:
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</span><span>1) Electrons are negative particles thar are around the nucleus of the atom (in regions called orbitals).
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2) Protons are positive particles that are inside the nuclus of the atom.
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<span>3) The nucleus of the atom has the same number of protons as electrons are in the orbitals of the atom.
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4) The atoms are neutral (neither positive nor negative) because there are the same number of electrons and protons and their charge are of the same magnitude but different sign: (+) + (-) = 0: positive + negative = neutral.</span>