7. What element is represented by this symbol? 25?

12

Manganese

Carbon

Magnesium

Iron

Answerd. may include all of these are many definitions of bases: the  brønsted-lowry definition of acids and bases says that bases are proton acceptors.the arrhenius definition of acids and bases says that bases increase [oh⁻] in solution (thereby producing oh⁻ ions)the lewis definition of acids and bases says that bases donate electron pairs.therefore, the sensible answer is that a base may include all of the described characteristics.

Adialysis unit requires 78.5 l of water.the estimated digit is 5. 

Ithink it's the third answer