Answer:
The answer is B. balanced forces
Let's eliminate these one by one.
The first pair would not be the same, as X would most likely be in group IA, and Y would be in group VIIA, because of their tendency to gain and lose electrons.
The second pair would also violate the same rule, but X would most likely be in group IIA, and Y would most likely be in group VIA.
The third pair would not be the same, as X is most likely in group VIIA, and since Y has eight valence electrons, it is most likely a noble gas.
The final pair has X with atomic number 15, making it phosphorous. Phosphorous wants to gain 3 electrons to have a full octet of 8 outer "valence" electrons, and Y would also like to gain 3 electrons. This means it is possible that the final pair would be in the same group.
Answer:
90%
Explanation:
Percentage yield = ?
Theoretical yield = 50g
Actual yield = 45g
To calculate the percentage yield of a compound, we'll have to use the formula of percentage yield which is the ratio between the actual yield to theoretical multiplied by 100
Percentage yield = (actual yield / theoretical yield) × 100
Percentage yield = (45 / 50) × 100
Percentage yield = 0.9 × 100
Percentage yield = 90%
The percentage yield of the substance is 90%
Okay so because of the difference in density a simple method for telling the difference between the two is to put a sample in a container with oil, because water has a higher density than the oil it would sink to the bottom but alcohol on the other hand is lighter than oil and would float on top of the oil.
However with this question I think that what you would do is use the ice to find out what the substance is, it would float on top of the liquid if it were water because the water is denser than ice but the ice would sink if it was alcohol because the alcohol is less dense than ice.
I hope this helps you, good luck : )
Answer:
The radioactive isotopes within these brains typically record the ages of the grains-not the time when the sedimentary rock was formed, making it difficult to date using radiometric dating. The half-life of U-235 is 704 million years.
Explanation:
hope this helps but if i'm wrong then i'm sorry..
