In the ground state, an atom of which element has seven valence electrons?
1.
sodium
2.
phosphorus
3.
nitrogen
4.
fluorine

Great amounts of electromagnetic energy from our sun and other bodies in space travel through space. which is a logical conclusion about these electromagnetic waves? their energy must be very their frequency must be very low these waves can travel without a medium they only travel through a vacuum of space

The kw for water at 0 °c is 0.12× 10–14 m2. calculate the ph of a neutral aqueous solution at 0 °c.

The diagin dilutepage 6 of 12a6a5(a)fluorine, chlorine, bromine and iodine are placed in the same group of theperiodic table.state the common name used to describe elements in this group.(i)state the group in which the elements are placed and explain whythey are placed in that group.(ii)which of the above named elements is a solid at roomtemperature and pressure?