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Answer:
Elements in the same period have the same (number of electron shells)
True, because diatomic elements (H2, O2, F2, Br2, I2, N2, Cl2) consist of only one element but are molecules with covalent bonds.
Tree sap is a viscoelastic polymer, which means it's not really a solid but a very viscous (sticky) fluid. It's fluidity ensures that it can properly <span>seal the spaces between the planks on wooden boats. Not only that, the pitch sap is hydrophobic - it is water resistant as well. </span>
