Answer to the first one is that they are brittle. This is not true because they have strong bonds
Answer is: metal is lead with density of 11,4 g/cm³.
Text that missing: a sample of an unkwown metal has a mass of 35,4 g and a volume of 3,11 cm³.
m(metal) = 35,4 g.
V(metal) = 3,11 cm³.
d(metal) = m(metal) ÷ V(metal)
d(metal) = 35,4÷ g ÷ 3,11 cm³
d(metal) = 11,4 g/cm³.
The opposite type of reaction (where energy is taken in from the surroundings of a reaction and thus the energy of the reactants is lower than that of the products) is called an endothermic reaction
Generally, a liquid freezes exothermally on cooling and a crystal melts endothermally on heating.
The 6 phase changes are vaporization, condensation, freezing, melting, sublimation, and deposition
