Answer:
Thorium-234 option a .......
[k]+ [:CL:] -
k has no dots and CL had 8 so 2 on each side of CL and then CL is negative after the closed brackets
Answer:
4.66 x 10^8 yr
Explanation:
The age of the rock can be calculated using the equation:
ln (N/N₀) = - kt where N is the quantiy of radioisotope decayed and N₀ is the initially quantity present of the radioisotope; k is the decay constant, and t is the time.
Now from the data , we have 78 argon-40 atoms for every 22 potassium-40 atoms, we can deduce that originally we had 22 + 78 = 100 atoms of potassium-40 so this is our N₀.
When we look at the equation, we see that k is unknown, but we can calculate it from the half-life which is given by the equation:
k = 0.693/ t half-life = 0.693/ 1.3 x 10⁹ yr = 5.33 x 10⁻¹⁰ yr⁻¹
Now we are in position to answer the question.
ln ( 78/100 ) = - (5.33 x 10⁻¹⁰ yr⁻¹ ) t
- 0.249 = - 5.33 x 10⁻¹⁰ yr⁻¹ t
0.249/ 5.33 x 10⁻¹⁰ yr⁻¹ = t
4.66 x 10^8 yr
Answer:
The modern model recognizes particles in the atom, whereas Dalton’s model does not.
Explanation:
The modern model considers the atom to consist of electrons, protons, and neutrons.
A is wrong. The modern model of the atom is widely accepted.
B is wrong. Dalton assumed that all atoms are identical. The modern model recognizes that there are isotopes of atoms.
D is wrong. The modern model explains emission spectra. Dalton's model does not.
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