The penetrating power of alpha rays, beta rays, and gamma rays varies greatly. Alpha particles can be blocked by a few pieces of paper. Beta particles pass through paper but are stopped by aluminum foil. Gamma rays are the most difficult to stop and require concrete, lead, or other heavy shielding to block them.
Answer:
357 g of the transition metal are present in 630 grams of the compound of the transition metal and iodine
Explanation:
In any sample of the compound, the percentage by mass of the transition metal is 56.7%. This means that for a 100 g sample of the compound, 56.7 g is the metal while the remaining mass, 43.3 g is iodine.
Given mass of sample compound = 630 g
Calculating the mass of iodine present involves multiplying the percentage by mass composition of the metal by the mass of the given sample;
56.7 % = 56.7/100 = 0.567
Mass of transition metal = 0.567 * 630 = 357.21 g
Therefore, the mass of the transition metal present in 630 g of the compound is approximately 357 g
Answer:
mass HF = 150.05 g
Explanation:
- SiO2(s) + 4HF(g) → SiF4(g) + 2H2O(l)
⇒ Q = (ΔH°rxn * mHF) / (mol HF * MwHF )
∴ MwHF = 20.0063 g/mol
∴ mol HF = 4 mol
∴ ΔH°rxn = - 184 KJ
∴ Q = 345 KJ
mass HF ( mHF ):
⇒ mHF = ( Q * mol HF * MwHF ) / ΔH°rxn
⇒ mHF = ( 345 KJ * 4mol HF * 20.0063 g/mol ) / 184 KJ
⇒ mHF = 150.05 g HF
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