<h3>
Answer:</h3>
42960 years
<h3>
Explanation:</h3>
<u>We are given;</u>
- Remaining mass of C-14 in a bone is 0.3125 g
- Original mass of C-14 on the bone is 80.0 g
- Half life of C-14 is 5370 years
We are required to determine the age of the bone;
- Remaining mass = Original mass × 0.5^n , where n is the number of half lives.
Therefore;
0.3125 g = 80.0 g × 0.5^n
3.90625 × 10^-3 = 0.5^n
- Introducing logarithm on both sides;
log 3.90625 × 10^-3 = n log 0.5
Solving for n
n = log 3.90625 × 10^-3 ÷ log 0.5
= 8
- Therefore, the number of half lives is 8
- But, 1 half life is 5370 years
- Therefore;
Age of the rock = 5370 years × 8
= 42960 years
Thus, the bone is 42960 years old
The reaction is a displacement reaction. Iron is more reactive than copper. Hence, it displaces copper,forming iron II sulfate and copper metal.
This reaction is an exothermic reaction, hence it releases energy. The colour change indicates that iron has displaced copper.
Answer:
The volume of hydrogen gas produced at STP is 4.90 liters.
Explanation:
Moles of aluminium =
According to reaction , 2 moles of aluminium gives 3 moles of hydrogen gas.
Then 0.1333 moles of aluminium will give:
of hydrogen gas
Volume of 0.2 moles of hydrogen gas at STP = V
Temperature at STP = T = 298.15 K
Pressure at STP = P = 1 atm
n = 0.2 mol
PV = nRT (Ideal gas equation)
The volume of hydrogen gas produced at STP is 4.90 liters.
Answer:
Shiny solid. Conducts heat and electricity. Easily bends
Explanation:
Answer:
2.7 x 10^-19 J
Explanation:
The formula needed for this problem is
E = hν
where E = energy, h = Planck's constant = 6.626x10^-34 and ν is the frequency
c = λν
where c = speed of light = 3x10^8, and λ = wavelength
3x10^8 = 7.35x10^-7 . ν
ν = 4.08 x 10^14 Hz
E = 6.626x10^-34 . 4.08x10^14 = 2.7 x 10^-19 J
