What is the purpose of a spectroscope? * A. to spread light into different wavelengths
B. to study a star's composition
C. to study a star's temperature
D. all of the above

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What layer of the atmosphere is directly above the troposphere?

There are 6.022, 104 atoms of hg in 1 mole of hg the number of atoms in 45 moles of hg can be found by multiplying 4.5 by 6.022, 102 which is the number of atoms in 4.5 moles of hg, correctly written in scientific notation with the correct number of significant figures? 0 21,109 0 21,100 271, 1024 27.099, 100 mark this and retum save and exit submit

The mass of a neutron is equal to the mass of a proton plus the mass of an electron. true or false false true