Answer:
Model A
Explanation:
Model A represents an atom that is more reactive than the others represented.
Valence electrons actually determine the reactivity of elements. They also determine the properties of elements.
Elements with one valence electron are highly reactive because they need low energy to remove them. They can either gain more electrons to become stable or they share/give out their electrons.
Therefore, Model A is the correct answer because it has one valence electron and its valence electron is farther from the nucleus thereby this makes it more reactive.
Answer:
C
) 2, 1, 2
Explanation:
The given reaction is synthesis reaction in which lithium and bromine react to form lithium bromide.
Chemical equation:
Li + Br₂ → LiBr
Balanced chemical equation:
2Li + Br₂ → 2LiBr
Step 1:
Li + Br₂ → LiBr
left hand side Right hand side
Li = 1 Li = 1
Br = 2 Br = 1
Step 2:
Li + Br₂ → 2LiBr
left hand side Right hand side
Li = 1 Li = 2
Br = 2 Br = 2
Step 3:
2Li + Br₂ → 2LiBr
left hand side Right hand side
Li = 2 Li = 2
Br = 2 Br = 2
Chemical properties of elements are primarily determined by the electrons but not by neutrons. Therefore, the isotopes of the same element have similar chemical behavior. (a) The atomic number is 17, so there are 17 protons and 17 electrons. The mass number is 35, so there are 18 (=35-17) neutrons. Hope this helps. :)
