Answer:
density of cube =11.605 g/cm³
Explanation:
density of a substance is the mass per unit volume of that substance.
the density of a substance = 
volume of a cube = l³,
l = 19.0mm , lets convert mm to cm
1mm = 0.1cm, thus, 19mm =19*0.1 =1.9cm
length of cube =1.9cm
volume of cube = 1.9³
density of cube = 
density of cube =11.605 g/cm³
J.J. Thomson discovered electrons and noticed that an atom can be divided. Also, he concluded atoms are made of positive cores and negatively charged particles within it.
Answer:
B -- Cobalt and iron
Explanation:
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