Answer:
calcium ca
Explanation:
We can see here that the only element that is on the same group (column) as Ba (Barium) is Calcium (Ca).
Answer:
c. can have a large cumulative effect
Explanation:
Noncovalent interactions between molecules are weaker than covalent interactions. Noncovalent interactions between molecules are of various types which include van der Waals forces, hydrogen bonding, and electrostatic interactions or ionic bonding.
van der Waals forces are weak interactions found in all molecules. They include dipole-dipole interactions - formed due to the differences in the electronegativity of atoms - and the London dispersion forces.
Hydrogen Bonds results when electrons are shared between hydrogen and a strongly electronegative atoms like fluorine, nitrogen, oxygen. The hydrogen acquires a partial positive charge while the electronegative atom acquires a partial negative. This results in attraction between hydrogen and neighboring electronegative molecules.
Ionic bonds result due to the attraction between groups with opposite electrical charges, for example in common salt between sodium and chloride ions.
Even though these noncovalent interactions are weak, cumulatively, they exert strong effect. For example, the high boiling point of water and the crystal structure of ice are due to hydrogen bonding.
K + S = K2S
Potassium reacts with sulfur to produce potassium sulfide
Answer:
8 to 8.5 since that is the recommended and people usualy sleep more than that
