Answer: Na, S, Cl
Explanation:
Atomic size decreases as one moves from left to right on the periodic table with elements in the same period. This is as a result of the electrons increasing in the outer circle and thus being drawn to the protons in the nucleus which will lead to the outer shell area decreasing.
Sodium (Na) comes before Sulfur (S) which comes before Chlorine (S) so this is the decreasing order as they are all in the same period.
The molality is 0.54 M when 1.34 moles of NaCl is present in 2.47 kg of solvent.
<u>Explanation:</u>
Molality is the measure of how much of amount of solute is dissolved in the solvent. So it is calculated as the ratio of moles of solute to the grams of solvent.

As in this case, the solute is NaCl and solvent is unknown. So the moles of solute is given as 1.34 moles and the mass of solvent is given as 2.47 kg.
Hence, 
Thus, the molality is 0.54 M when 1.34 moles of NaCl is present in 2.47 kg of solvent.
Answer:
2600 kg has 4 significant figures
Explanation:
Any different number to zero is a significant figure
For example, 1.8 → 2 significant figures
When you have 0 in the middle of two numbers, we consider it as a significant number
For example, 3.02 → 3 significant figures
When you have 0 on the left in the measure, we do not consider as a sgnificant figures
For example 0.0010 → 2 significant figures (10)
3.0 → 2 significant figures (0 is on the right, not the left)
Today, natural sciences<span> are more </span>commonly divided<span> into life </span>sciences<span>, such as botany and zoology; and physical </span>sciences<span>, which include physics, chemistry, geology, astronomy and materials </span>science<span>.</span>
Answer:

Explanation:
We have the number
. Standard notation would basically be this number without the
part.
To get rid of this part, we need to move the decimal point 6 places to the left (we go left because it's negative 6, indicating division).
So, when we move the decimal point 6 places to the left, the resulting number is:
, with 5 zeros after the decimal point before a nonzero number.
Thus, the answer is
.