As you move across the periodic table from groups 1-16, tends to decrease
A)electron shells or energy levels
B)reactivity
C)atomic mass
D)atomic number

The big bang nucleosynthesis theory states that elements were produced in the first few minutes of the big bang while elements have their origins in the interiors of stars, forming much later in the history of the universe.

Liv sheldon given the balanced equation for an organic reaction: c2h2 + 2cl2 → c2h2cl4 this reaction is best classified as *

3. how much energy in joules is required to evaporate .0005 kg of liquid ammonia to vapor at the same temperature? 4. how much energy ( in megajoules ) is given up by .75 kg of water at 0c when it freezes to form ice at 0c? 5. explain how heat works between and at critical temperatures?