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: A thing that died a long time ago, and it's bones were preserved in the ground.
Explanation:
Because yes
Answer:
6813.7g
Explanation:
Calculate the mass
Let x be the mass
If 1 mol of Fe has a mass of 55.85 g
1 mol =55.85g
122mol= x
we have x= 122•55.85g=6813.7g
Answer:
d. white blood cells
Explanation:
It is the white blood cells that have the least tendency to cross the blood- brain barrier.
Blood- brain barrier is psychological barrier and restricts substances that circulate into the blood from crossing over the central nervous system.
Water, glucose as well as sodium ions can easily cross the barrier. As these are good for body supply energy to the brain.
<em>V = 151 mL = 151 cm³</em>
<em>d = 0,789 g/mL = 0,789 g/cm³</em>
--------------------------------------
d = m/V
m = d×V
m = 0,789×151
<u>m = 119,139g</u>
