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alisha [4.7K]
3 years ago
14

Is anyone good at chemistry if so can someone please help me NO LINKS PLEASE

Chemistry
1 answer:
joja [24]3 years ago
3 0

Answer:

1. Mass of New atom = 208

2. Atomic number of the new atom is 82

3. Symbol of the new atom is Pb

Explanation:

²¹²₈₄Po —> ⁴₂He + ᴬZX

1. Determination of the mass A of the new atom.

212 = 4 + A

Collect like terms

212 – 4 = A

208 = A

A = 208

Therefore, the mass of the new atom is 208

2. Determination of the atomic number of the new atom.

84 = 2 + Z

Collect like terms

84 – 2 = Z

82 = Z

Z = 82

Therefore, the atomic number of the new atom is 82

3. Determination of symbol of the new atom

The atomic number of the new atom is 82. Comparing the atomic number of the new atom (i.e 82) with those in the periodic table, the new atom is Lead.

Lead has a symbol of Pb

Thus,

Mass of new atom (A) = 208

Atomic number of new atom (Z) = 82

Symbol of new atom (X) = Pb

Therefore,

ᴬZX = ²⁰⁸₈₂Pb

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39.25 g of water (H₂O)

Explanation:

We have the following chemical reaction:

2 H₂ + O₂ → 2 H₂O

Now we calculate the number of moles of each reactant:

number of moles = mass / molar weight

number of moles of H₂ = 14.8 / 2 = 7.4 moles

number of moles of O₂ = 34.8 / 32 = 1.09 moles

We see from the chemical reaction that 2 moles of H₂ will react with 1 mole of O₂ so 7.4 moles of H₂ will react with 3.7 moles of O₂ but we only have 1.09 moles of O₂ available. The O₂ will be the limiting reactant. Knowing this we devise the following reasoning:

if        1 moles of O₂ produces 2 moles of H₂O

then  1.09 moles of O₂ produces X moles of H₂O

X = (1.09 × 2) / 1 = 2.18 moles of H₂O

mass = number of moles × molar weight

mass of H₂O = 2.18 × 18 = 39.25 g

Learn more about:

limiting reactant

brainly.com/question/7144022

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The development of the universe would have been different without the universe in the sense that the young universe won't have enough mass to hold it together, and the universe would have simply floated apart. The behavior of the universe would have been different from what we observe now, and some physical laws that applies now will not apply to the universe.

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7 0
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Read 2 more answers
Identify the number of moles in 369 grams of calcium hydroxide. Use the periodic table and the polyatomic ion resource.
topjm [15]

Answer : The number of moles in 369 grams of calcium hydroxide is, 4.98 moles

Explanation : Given,

Mass of calcium hydroxide = 369 g

Molar mass of calcium hydroxide = 74.093 g/mole

Formula used :

\text{Moles of calcium hydroxide}=\frac{\text{Mass of calcium hydroxide}}{\text{Molar mass of calcium hydroxide}}

Now put all the given values in this formula, we get the moles of calcium hydroxide.

\text{Moles of calcium hydroxide}=\frac{369g}{74.093g/mole}=4.98mole

Therefore, the number of moles in 369 grams of calcium hydroxide is, 4.98 moles

7 0
3 years ago
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