Answer:
All of the elements in a period have the same number of atomic orbitals. For example, every element in the top row (the first period) has one orbital for its electrons. All of the elements in the second row (the second period) have two orbitals for their electrons.
Explanation:
Answer:first D. 88L
Second A 2*10^24
Explanation:
At stp 1 mole = 22.4L
mw Cl2= 70.9
280 g =280/70.9 moles, about 4
4*22.4 = about 88
aw Sr 87.6 —> 6.02214076*10^23 atoms = 1 mole
Answer: Rate law is, R= 6.02[A]¹[B]²
Explanation in attached image
Answer:

Explanation:
The unbalanced nuclear equation is

Let's write X as a nuclear symbol.

The main point to remember in balancing nuclear equations is that the sums of the superscripts and of the subscripts must be the same on each side of the reaction arrow.
Then
235 = 4 + A , so A = 235 - 4 = 231, and
92 = 2 + Z , so Z = 92 - 2 = 90
And your nuclear equation becomes

Element 90 is thorium, so
