In order of relative atomic mass.
Answer:
The larger the number of the energy level, the farther it is from the nucleus. Electrons that are in the highest energy level are called valence electrons. Within each energy level is a volume of space where specific electrons are likely to be located.
Answer:
B and E
Explanation:
These two options support the theory of plate tectonics.
Answer:
Explanation:
It makes sense because Helium and Hydrogen only hold 1 and 2 subsequent protons/neutrons and electrons. When the Big Bang happened the entire universe was so hot that it was impossible for elements to form since it was impossible for electrons to stay bound to the atoms. After a few seconds the universe began to cool enough for electrons to bond to atoms and create different elements. Since Helium and Hydrogen have 1 and 2 electrons subsequently we can assume that they were the first elements to be created. Also they are the most abundant elements in the Universe which backs up this theory.