It would be 23.46, since the next number is a 5 so we can round up.
Significant figures are:
ANY number that is not 0
Any 0 between two nonzero digits
Any 0 following a decimal (i.e 1.50)
Volume of water displaced is equal to the volume of the metal. So 41 - 20 = 21 ml. Density = mass / volume so density = 159 / 21 = 7.57 g/ml
a...if you had the fully extended periodic table, these elements would be between La and Hf in period 6 and Ac and Rf in period 7
Elements that are in the same columns (vertical) are chemically similar.
Carbon- Si
Cesium- Na
Krypton- Ar
Magnesium- Ca
Al- try Boron
Br try Cl
These are just the ones I picked but it could be any in the same column
