If the half-life of a sample of a radioactive substance is 30 seconds, how much would be left after 60 seconds? <span>
A. one-fourth</span>
i think its MIDDLE FINGERS UP IN THE SKY AND AT THESE AHOLE MODERATORS
Answer:
D.) Mg(NO₃)₂
Explanation:
Since magnesium (Mg) is a metal and nitrate (NO₃) is a polyatomic anion, they would combine to form an ionic compound. Magnesium would form the cation Mg²⁺ because it generally has 2 valence electrons. Nitrate always has a -1 charge.
In order for the overall compound to be neutral (have a charge of 0), there must be one Mg²⁺ and two NO₃⁻ ions in the compound (+2 + (-1) + (-1) = 0).
Therefore, the formula for the compound formed is Mg(NO₃)₂.
Answer:
The partial pressure of oxygen in the mixture is 296 mmHg.
Explanation:
The pressure exerted by a particular gas in a mixture is known as its partial pressure. So, Dalton's law states that the total pressure of a gas mixture is equal to the sum of the pressures that each gas would exert if it were alone.
This relationship is due to the assumption that there are no attractive forces between the gases.
So, in this case, the total pressure is:
PT=Phelium + Pnitrogen + Poxygen
You know:
- PT= 756 mmHg
- Phelium= 122 mmHg
- Pnitrogen= 338 mmHg
- Poxygen= ?
Replacing:
756 mmHg= 122 mmHg + 338 mmHg + Poxygen
Solving:
756 mmHg - 122 mmHg - 338 mmHg = Poxygen
Poxygen= 296 mmHg
<u><em>The partial pressure of oxygen in the mixture is 296 mmHg.</em></u>
D. Sublimation is a solid turning directly into a gas
