Answer:
2.15 mg of uranium-238 decays
Explanation:
For decay of radioactive nuclide-
where N is amount of radioactive nuclide after t time, 
is initial amount of radioactive nuclide and 
is half life of radioactive nuclide
Here 
, 
and 
So,
so, N = 2.446 mg
mass of uranium-238 decays = (4.60-2.446) mg = 2.15 mg
Answer:
Decreasing surface area of the solid in the liquid.
Explanation:
I don't know how to explain this without using. an example. So, here it is: If you were dipping bread in water, the bread would be completely soaked if you dipped the whole thing, but if you only allowed one part of the bread to be in the water, it would take longer for the water to soak all the way into it. The amount of surface area that is allowed to touch what is making the solid dissolve determines how quickly the whole thing will be dissolved.
Answer:
1.70
Explanation:
The molar mass of perchloric acid is 100.46 g/mol. The moles corresponding to 484 mg (0.484 g) are:
0.484 g × (1 mol/100.46 g) = 4.82 × 10⁻³ mol
4.82 × 10⁻³ moles are dissolved in 240 mL (0.240 L) of solution. The molar concentration of perchloric acid is:
4.82 × 10⁻³ mol/0.240 L = 0.0201 M
Perchloric acid is a strong monoprotic acid, that is, it dissociates completely, so [H⁺] = 0.0201 M.
The pH is:
pH = -log [H⁺] = -log 0.0201 = 1.70
True.
where the atom is the smallest (tiny) particle of an element, the atom may be neutral or ionized, and its size is around 100 picometers. The atom composed of a nucleus and one or more electrons (negative charge) bound to the nucleus, the nucleus contains protons (positive charge) and neutrons.
The charge of the cadmium cation is +2
