How much heat is needed to raise the temperature of 450.0 g H2O from 25.5 C to 50.0 C

There are main groups in the modern periodic table of elements

Astudent reacts 13 moles of iron with 21 moles of oxygen according to the following equation:

An atom's configuration based on its number of electrons ends at 3p4. another atom has seven more electrons. starting at 3p, what is the remaining configuration? 3p63d34s2 3p43d54s2 3p64s23d3 3p44s23d