Examine the following electron configuration: 1s22s22p63s23p64s2. How many valence electrons does this element contain?

Modern pennies are composed of zinc coated with copper. a student determines the mass of a penny to be 2.482 g and then makes several scratches in the copper coaling (to expose the underlying zinc). the student puts the scratched penny in hydrochloric acid, where the following reaction occurs between the zinc and the hcl (the copper remains undissolved): zn(s) + 2 hcl(aq) → h2(g) + zncl(aq)the student collects the hydrogen produced over water at 25 °c. the collected gas occupies a volume of 0.899 l at a total pressure of 79 j mmhg. calculate the percent zinc (by mass) in the penny. (assume that all the zn in the penny dissolves.)

Match the term to its description match term definition chemical energy a) internal energy caused by vibrations of atoms and molecules electrical energy b) electromagnetic energy that travels in waves radiant energy c) the movement of an electrical charge thermal energy d) potential energy stored in the bonds between atoms

In in , is to a 28.4-g (1-oz)−23.0 °c to −1.0 °c?