The third answer because there are two of each atom
A convergent plate boundary is formed when tectonic plates collide
Answer:
substance A is a liquid, while substance B is a liquid or gas
Answer:
All elements in the same group of the periodic table have the same number of valence electrons. This made it possible to compare the valence of the alien elements to the valence of elements from our periodic table, and match the alien elements to the correct group. For example, our group 14 elements all have 4 valence electrons, so the alien element with 4 valence electrons had to be part of group 14 also.
Answer:
Noble Gases
Explanation:
The Noble Gases have a full valence shell of 8 electrons. They are stable in that sense.