Answer:-
Alpha decay
Explanation:-
Uranium 238 has atomic number 92 and mass number 238.
Thorium 234 has atomic number 90 and mass number 234.
So, the change in atomic number as uranium 238 disintegrates into thorium234 = 92 – 90 = 2
So, the change in mass number as uranium 238 disintegrates into thorium234= 238 – 234 = 4
We know that when an alpha particle is emitted, the mass number decreases by 4 and the atomic number decreases by 2.
So when an atom of uranium 238 undergoes radioactive decay to form an atom of thorium-234, alpha decay has occurred.
I'd say false because copper is what they used to drink out of in the middle ages, and it caused them to get very sick, so I doubt they would use copper in your mouth.
Answer is: mass of unused sulfur is 5.87 grams.
Balanced chemical reaction: C + 2S → CS₂.
m(C) = 12.0 g; mass of carbon.
m(S) = 70.0 g; mass of sulfur.
n(C) = m(C) ÷ M(C).
n(C) = 12 g ÷ 12 g/mol.
n(C) = 1 mol; amount of substance.
n(S) = m(S) ÷ M(S).
n(S) = 70 g ÷ 32.065 g/mol.
n(S) = 2.183 mol.
From chemical reaction: n(C) : n₁(S) = 1 : 2.
n₁(S) = 1 mol · 2 = 2 mol.
Δn(S) = n(S) - n₁(S).
Δn(S) = 2.183 mol - 2 mol.
Δn(S) = 0.183 mol; amount of unused sulfur.
Δm(S) = 0.183 mol · 32.065 g/mol.
Δm(S) = 5.87 g.
It can be a compound or a single element. An element is a pure substance that cannot be separated into simpler substances by chemical or physical means. There are about 117 elements, but carbon, hydrogen, nitrogen and oxygen are only a few that make up the largest portion of Earth.
I would say pure substances
We're given the [OH⁻] as 8.34 × 10⁻¹² M. Using the formula pOH = -log[OH⁻], the pOH of this solution would be -log(8.34 × 10⁻¹²) ≈ 11.08.
The pOH is, for lack of a better term, the "opposite" of pH: A pOH of 7 is neutral; a pOH less than 7 is <em>basic</em>; and a pOH greater than 7 is <em>acidic</em>.
This follows from the relation, pH + pOH = 14. In this case, with a pOH of 11.08, our pH would be 14 - 11.08 = 2.92, which is acidic (pH < 7).
Thus, the correct answer choice is B.
