Answer:
in the presence of water H2O
Na2CO3 (S) --> 2Na+ (aq)+ (CO3)2-(aq)
One mole of sodium carbonate produces two moles of Na+ ions
Therefore 0.207 moles produces 0.414 moles of Na+ ions
= 0.414 moles of Na+ ions
Explanation:
In water
Na2CO3 --> 2Na+ (aq)+ (CO3)2-(aq)
In a limited reaction, the carbonate ion reacts with the water molecules as follows
(CO3)2-(aq) + H2O←→HCO3-(aq) + OH-(aq)
sodium carbonate or soda ash dissolves in water to give 2 sodium cations and one carbonate anion
<h2>
Hello!</h2>
The answer is:
The empirical formula is the option B. 
<h2>
Why?</h2>
The empirical formula of a compound is the simplest formula that can be written. On the opposite, the molecular formula involves a variant of the same compound, but it can be also simplified to an empirical formula.

We are looking for a formula that cannot be simplified by dividing the number of molecules/atoms that conforms the compound.
Let's discard option by option in order to find which formula is an empirical formula (cannot be simplified)
A. 
It's not an empirical formula, it's a molecular formula since it can be obtained by multiplying the empirical formula of the same compound.

B. 
It's an empirical formula since it cannot be obtained by the multiplication of a whole number and the simplest formula. It's the simplest formula that we can find of the compound.
C. 
It's not an empirical formula, it's a molecular formula since it can be obtained by multiplying the empirical formula of the same compound.

D. 
It's not an empirical formula, it's a molecular formula since it can be obtained by multiplying the empirical formula of the same compound.

Hence, the empirical formula is the option B. 
Have a nice day!
1. the producer is the wheat/plant (producers create their own energy, example is photosynthesis in plants)
2. the consumer is the bird (hint all consumers have mouths. they have to eat/ drink something to produce energy)
<span>If you give it a good search, the most used answer would probably be as follows,
</span><span>In 1914 Henry Moseley found a relationship between an element's X-ray wavelength and its atomic number (Z), and therefore rearranged the table by nuclear charge / atomic number rather than atomic weight. Before this discovery, atomic numbers were just sequential numbers based on an element's atomic weight. Moseley's discovery showed that atomic numbers had an experimentally measurable basis.
</span>
Hope this helps!
Answer:
Individual versus nature
Explanation:
The type of conflict is <em>individual</em><em> </em><em>versus</em><em> </em><em>nature</em><em> </em>because the cat faced many problems in nature such as facing the mouse, grass, people, etc. These are all considered as nature
<em>PLEASE DO</em><em> </em><em>MARK ME</em><em> </em><em>AS BRAINLIEST</em><em> </em><em>IF</em><em> </em><em>MY ANSWER</em><em> </em><em>IS HELPFUL</em><em> </em><em>;</em><em>)</em><em> </em>