Science Homework Help

True or false?

       A. Atoms form ions by losing or gaining

electrons.

       B Electrons have a larger mass than protons and neutrons.

       C. All atoms of a particular element have the same atomic number.

       D Nitrogen and phosphorus both have 3 valence electrons.

       E. Technology is the application of scientific knowledge to serve

            practical purposes..

       F.  The maximum possible number of electrons in the third energy

              Level is 8.

       G. In chemical reactions the group 2A elements gain 2 electrons.

       H. A molecule consists of a cation (+ ion) and anion (- ion) held

             together by attraction of the opposite charges.

      I.  The bonding in a water molecule is best described as polar covalent. 

      J.  Except for He the noble gases (group 8A) have 8 valence electrons.