Answer:
The amount left after 49.2 years is 3mg.
Explanation:
Given data:
Half life of tritium = 12.3 years
Total mass pf tritium = 48.0 mg
Mass remain after 49.2 years = ?
Solution:
First of all we will calculate the number of half lives.
Number of half lives = T elapsed/ half life
Number of half lives = 49.2 years /12.3 years
Number of half lives = 4
Now we will calculate the amount left after 49.2 years.
At time zero 48.0 mg
At first half life = 48.0mg/2 = 24 mg
At second half life = 24mg/2 = 12 mg
At 3rd half life = 12 mg/2 = 6 mg
At 4th half life = 6mg/2 = 3mg
The amount left after 49.2 years is 3mg.
Answer:
hi!
Explanation:
The Mohs Hardness Scale ranks the order of hardness of minerals and some common objects. For example, your fingernail can scratch the minerals talc and gypsum, with a hardness of 2 or lower. A copper penny can scratch calcite, gypsum, and talc.
One of the most important tests for identifying mineral specimens is the Mohs Hardness Test.
This test compares the resistance of a mineral to being scratched by ten reference minerals known as the Mohs Hardness Scale (see table at left).
The test is useful because most specimens of a given mineral are very close to the same hardness. This makes hardness a reliable diagnostic property for most minerals.
"Hardness" is the resistance of a material to being scratched. The test is conducted by placing a sharp point of one specimen on an unmarked surface of another specimen and attempting to produce a scratch.
V(HNO₃) = 50.0 mL in liters = 50.0 /1000 =0.05 L
M(HNO₃) = 1.50 M
Number of moles HNO₃ :
n = M x V
n = 1.50 x 0.05
n = 0.075 moles of HNO₃
HNO₃ + NaOH = H₂O + NaNO₃
1 mole HNO₃ -------- ---1 mole NaOH
0.075 moles HNO₃ ---- ?
moles NaOH = 0.075 * 1 / 1
= 0.075 moles of NaOH
V ( NaOH ) :
M = n / V
0.81 = 0.075 / V
V = 0.075 / 0.81
V =<span> 0.0925 L or 92.5 mL </span>
<span>hope this helps!</span>
Explanation:
the answer is true because I had this question and got it right
Less dense because there mainly gas
