What causes the high luster of a metal? a
excitation of electrons into empty orbitals
b mobility of electrons
C easily ionizable metal atoms
d their low melting points

d their low melting points

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astronomers such as edwin hubble.

they it depends on if one believes about radioactivity, they make a geiger counter beep but maybe it was going to beep anyway electronics do wierd things all the time or it was programmed to beep near certain metals.