Formula units in 450 g of 
is 1.93 × 10²⁴ formula units.
<u>Explanation:</u>
First we have to find the number of moles in the given mass by dividing the mass by its molar mass as,
Now, we have to multiply the number of moles of Na₂SO₄ by the Avogadro's number, 6.022 × 10²³ formula units/mol, so we will get the number of formula units present in the given mass of the compound.
3.2 mol × 6.022 × 10²³ = 1.93 × 10²⁴ formula units.
So, 1.93 × 10²⁴ formula units is present in 450g of Na₂SO₄.
Carbon dating has<span> given archeologists a more accurate method by which they </span>can<span> determine the age of ancient artifacts. The </span>halflife<span> of </span>carbon 14<span> is </span>5730<span> ± 30 </span>years<span>, and the method of dating lies in trying to determine how </span>much carbon 14<span> (</span><span>the radioactive isotope of carbon) is present in the artifact and comparing it to levels</span>
Answer:
See the answer below
Explanation:
<em>First, it should be understood that an endothermic reaction is one that absorbs energy in the form of heat from the surrounding.</em> The products of endothermic reactions usually have higher energy than their reactants. Hence, the ΔH° which is referred to as the enthalpy change is usually positive.
<u>Forgetting to cover the coffee-cup calorimeter means some of the heat energy absorbed by the reactants would be exchanged back to the surroundings - a loss.</u> It also means that the enthalpy change would be smaller compared to if the cup had been covered because some of the heat has been lost to the surrounding.
Answer:
Explanation:
Firstly, it should be noted that atomic number (number of protons) determines element. And the element with the atomic number 10 (10 protons) is Neon. Hence, Neon-10 (₁₀Ne) is the answer.
Note that sodium has an atomic number of 11. Also, number of protons is usually equal to the number of electrons in neutral atoms, this is because the total number of positive particles (protons) must be equal to the total number of negative particles (electrons) to give a neutral atom.
Answer:
An atom of neon-20 has one fewer proton and two fewer neutrons than an atom of sodium-23.
Explanation:
Neon - 20 and Sodium - 23
Neon - 20
Protons = 10
Neutrons = 10
Sodium - 23
Protons = 11
Neutrons = 12
With the information above and checking the options;
An atom of neon-20 has one fewer proton and two fewer neutrons than an atom of sodium-23.
This option is correct.
