From literature, we would find that the half life of Uranium-238 is equal to 4.5x10^9 years. This is the same number of years to obtain 1/2 kg of Lead-206. Hope this answers the question. Have a nice day.
Hci acid its high preety cool
In this question, XB3(aq) is an ionic compound which will have the releasing of 3 B⁻ ions ions in water for every molecule of XB3 that dissolves.
XB3(s) --> X+(aq) + 3 B⁻(aq)
[B⁻] = 0.22 mol XB3/1L × 3 mol B⁻ / 1 mol XB3 = 0.66 M
The answer to this question is [B⁻] = 0.66 M
Answer:
(4) CuO + H₂ → Cu + H₂O.
Explanation:
<em>(1) Cu + 2AgNO₃ → Cu(NO₃)₂ + 2Ag.</em>
It is considered as a single replacement reaction that Cu replaces Ag in its salt AgNO₃.
<em>(2) 2Cu + O ₂ → 2CuO.</em>
It is a combustion reaction that Cu reacts with oxygen results CuO.
<em>(3) CuCO₃ → CuO + CO₂.</em>
It is a decomposition reaction that CuCO₃ is decomposed to CuO and CO₂.
<em>(4) CuO + H₂ → Cu + H₂O.</em>
It is considered as a synthesis reaction that two reactants CuO and hydrogen are reacted to produce Cu and H₂O.
<em>So, the right choice is: (4) CuO + H₂ → Cu + H₂O.</em>
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Answer:
See explanation
Explanation:
The p orbital is threefold degenerate. This implies that the p-sublevel is composed of three orbitals; px, py and pz.
According to Hund's rule, electrons occur singly when filling degenerate orbitals before pairing takes place. Since the three orbitals are degenerate, any of px, py or pz may be first filled.
If one lobe of any of the px, py or pz is first filled, the next electron must go into the next degenerate orbital. When all are filled, pairing of electron spins may now begin.
