The half-life of Th-232 is 1.405 × 10¹⁰ years
Time elapsed = 2.8 x 10⁹ years
Equation of radioactive decay:
A = A₀ = (1/2)^ t/t₁/₂
where A₀ is the initial amount, A is the amount after time t, t₁/₂ is the half file
The fraction of thorium-232 that remains in the rock after 2.8 billions years is,
A/A₀ = (1/2) ^ (2.8 x 10⁹/ 1.405 × 10¹⁰) = 0.871
Therefore, the percentage of thorium-232 in the rock that was dated at 2.8 billions year = 87.1%
Answer:
The property of water which makes it to attach or stick to another surface is Adhesion.
Explanation:
Adhesion is the characteristic ability a substance possess to stick to other substances. This is as a result of the covalent bond existing between the two hydrogen atoms and the one oxygen atom in the water molecule.
An example of the property of Adhesion is a water drop that stuck to the end of the pine needles
Density--<span>1.0g/cm3
Gravity-- </span><span>2.65g/cm3
</span>
Answer:
3300.85 g
Explanation:
Given data:
Mass of ZnCl₂ produced = ?
Mass of H₂ produced = 49.8 g
Solution:
Chemical equation:
Zn + 2HCl → ZnCl₂ + H₂
Number of moles of H₂:
Number of moles = mass/molar mass
Number of moles = 49.8 g/ 2.056 g/mol
Number of moles = 24.22 mol
Now we will compare the moles of H₂ with ZnCl₂ form balance chemical equation.
H₂ : ZnCl₂
1 : 1
24.22 : 24.22
Mass of ZnCl₂:
Mass = number of moles × molar mass
Mass = 24.22 × 136.286 g/mol
Mass = 3300.85 g
Answer:
it burns things which would be burned easily by lightning, and then people put the fire out immediately. If the dried plants that they are lighting on fire are hit by lightning, it can lead to a massive fire without anyone realizing.
