The mass of ore required is
21 700 t.
r = 750 cm
V =
=
= 1.767 × 10⁹ cm³
The density of lead is 11.34 g/cm³.
So mass of lead sphere = 1.767 × 10⁹ cm³ ×
= 2.004 ×10¹⁰ g
2.004 ×10¹⁰ g ×
= 2.004 × 10⁷ kg
2.004 × 10⁷ kg ×
= 2.004 × 10⁴ t
92.5% efficiency means 92.5 t Pb per 100 t of ore.
Mass of ore = 2.004 × 10⁴ t Pb ×
= 2.17 × 10⁴ t ore = 21 700 t ore
Answer:
120g
Explanation:
Step 1:
We'll begin by writing the balanced equation for the reaction.
Sn + 2HF —> SnF2 + H2
Step 2:
Determination of the number of mole HF needed to react with 3 moles of Sn.
From the balanced equation above,
1 mole of Sn and reacted with 2 moles of HF.
Therefore, 3 moles Sn will react with = 3 x 2 = 6 moles of HF.
Step 3:
Conversion of 6 moles of HF to grams.
Number of mole HF = 6 moles
Molar Mass of HF = 1 + 19 = 20g/mol
Mass of HF =..?
Mass = number of mole x molar Mass
Mass of HF = 6 x 20
Mass of HF = 120g
Therefore, 120g of HF is needed to react with 3 moles of Sn.
Answer:
B.
the passage of genetic instructions from one generation to the next generation.
These are called genes. One mate reporduces with another made and the genetic buildup merges 50 % and 50% with genetics(if it's meiosis), or DNA codes from the parents to the offspring that then possess some of the genes. That shows heridity.
Answer:
Total pressure 5.875 atm
Explanation:
The equation for above decomposition is
rate constant 
Half life 
Initial pressure 
Pressure after 3572 min = P
According to first order kinematics
solving for P we get
P = 2.35 atm
initial 4.70 0 0
change -2x +2x +x
final 4.70 -2x 2x x
pressure of
after first half life = 2.35 = 4.70 - 2x
x = 1.175
pressure of 
after first half life = 2x = 2(1.175) = 2.35 ATM
Total pressure = 2.35 + 2.35 + 1.175
= 5.875 atm
An orbital that penetrates into the region occupied by core electrons is less shielded from nuclear charge than an orbital that does not penetrate and therefore has a lower energy.
Explanation:
The only true statement from the given options is that "an orbital that penetrates into the region occupied by core electrons is less shielded from nuclear charge than an orbital that does not penetrate and therefore has a lower energy." Inner orbitals which are also known to contain core electrons feels the bulk of the nuclear pull on them compared to the outermost orbitals containing the valence electrons.
- The nuclear pull is the effect of the nucleus pulling and attracting the electrons in orbitals.
- This pull is stronger for inner orbitals and weak on the outer ones.
- The outer orbitals are said to be well shielded from the pull of the nuclear charge.
- Also, based on the quantum theory, electrons in the outer orbitals have higher energies because they occupy orbitals at having higher energy value.
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