<span>The answer is deceleration. Acceleration is the general term to refer to the change in velocity. Acceleration = change in velocity / change in time. When you want to highlight the fact that the change in velocity is a decrease in the magnitude, you can use the term deceleration, which means that the acceleration is negative.</span>
Answer:
31.60% phosphorus
Explanation:
To find the percent by mass, you first calculate the total mass and then the mass of phosphorus, and finally divide phosphorus mass by total.
Phosphorus mass: the molar mass of P is 30.97 g/mol, and since there's 1 mole of P, we just have 30.97 g.
Total mass: we add all the molar masses of the components together.
We have 3 moles of H, so we multiply 3 by 1.008 g/mol = 3.024 g H.
We already calculated the mass of phosphorus: 30.97 g P.
We have 4 moles of O, so we multiply 4 by 16.00 g/mol = 64.00 g O.
The total is then the sum: 3.024 + 30.97 + 64.00 = 97.994 g ≈ 97.99 g
Now, to find the percentage, we take 30.97 g P and divide by 97.99:
30.97/97.99 ≈ 0.3160 ⇒ 31.60% P
Thus, the answer is 31.60% phosphorus.
Hope this helps!
Answer:
Lead Pb
Explanation:
Firstly, we need to know what occurs when a radioisotope emits an alpha particle. An alpha particle is an helium atom. When an isotope emits an alpha particle, it loses an helium atom corresponding to subtracting 4 from its mass number and 2 from its atomic number. This of course coupled with the release of radiation.
Now, we polonium has a proton number of 84 and a mass number of 210. Subtracting 2 and 4 respectively from its proton and mass numbers will yield 82 and 206 proton and mass numbers respectively.
Hence, the decomposition of the Po-210 isotope will yield an element with 82 proton number and 206 mass number. This corresponds to the element Lead.
210Po ——> 206Pb + alpha particle + radiation
Answer:
Theoretical yield: 13.9 g
Percent yield: 94 %
Explanation:
The reaction is:
CaCO₃ → CaO + CO₂
We see that the reaction is correctly balanced.
1 mol of calcium carbonate can decompose to 1 mol of calcium oxide and 1 mol of carbon dioxide.
We convert the mass to moles: 24.8 g . 1mol / 100.08g = 0.248 moles
As ratio is 1:1, 0.248 moles of salt can decompose to 1 mol of oxide.
We convert the moles to mass: 0.248 mol . 56.08g /1mol = 13.9 g
That's the theoretical yield.
To determine the percent yield we think:
(Determined yield / Theoretical yield) . 100 → (13.1 / 13.9) . 100 = 94 %
