5 g potassium WI Wa grams Itbe the provided box. H content 1 are of a 8 standard Check my 'opeles ! wolk 159 'Bu There are about...

In 78.20 g of potassium, there are ______ potassium atoms present.

With this problem were given the fact that we have 1/2 cup Serving of cereal has 180 milligrams of potassium, and this problem tells that is 5% of the daily recommended daily allowance of potassium. So the problem is asking how many grams is the daily allowance? So we have to do a couple things here. We can disregard the fact that it's 1/2 cup serving because that doesn't have anything to do with what we're looking for. But first we need to figure out how many milligrams are in the daily allowance, and then we have to convert to grams to solve finish the problem. So let's see here. So we have 5% of the daily allowance. So how many five percents go into 100%? Well, we know that 20 times five is 100 so we need to multiply 180 by 20. So when we do that, we end up with an answer of 3600 milligrams are in a daily allowance, and now we have to convert milligrams two grams. So in order to cover milligrams two grams, we must know the relationship between the two and if we use our table, we know that 1000 milligrams is equal to one gram. So in order to solve for this, we need to divide 3600 by 1000 to give us an answer of 3.6 grams of potassium are in the daily allowance.

It's providing nanoscale explanation for the fact that even though the mass of potassium is only slightly less than calcium the density potassium is twice as less than solid calcium. So um the calcium atoms possess a smaller radius. Mhm. As compared to the potassium atoms. Mhm. Yeah. Mhm. Therefore on packing. Mhm. Mhm acquire less volume. Yeah. As compared to potassium. Mhm. Yeah. As they acquire less volume. Yeah. Yeah. Mhm. They will in turn have a higher density. Mhm. Mhm.

Hi there for this problem. We're trying to determine how Maney grams of potassium we have in 57.4 g of potassium sulfate. Potassium sulfate is going to be K two s 04 because potassium has a plus one charge and sulfate has a to minus charge. So we need to potassium so that our charges end up neutral. Right. This is going to be a percentage composition problem, which means we're going to have to find the percent of potassium in this compound. We're gonna find the percent by mass. And then we could take that percentage and multiplied by the total mass of the compound to figure out how much potassium was in there. So let's get started. The first thing we have to do is calculate the percentage composition of potassium. So I'm going to list out the elements found in this compound. We have potassium, we have sulfur, and we have oxygen. Looking at the periodic table. I see that potassium is mass is 39 0.10 g. I'm gonna multiply that by two. Because in my formula K two s 04 there are two potassium Seoul furs. Mass is 32.7. There's only one sulfur yeah, and oxygen. There are four oxygen's in my formula. Oxygen's masses 16.0 g. Adding these all together I get a total mass for this compound of 1 74 0.27 So Mueller Mass of the compound is 1 74.27 g per mole. Remember, I am interested in the potassium in this problem. So did determine the percent of potassium in this problem. I'm going to take the grams of the potassium and divided by the total mass of the compound. So let's do that step. The mass of the potassium two times 39.10 is 78 0.20 g, and the total mass of the compound is that 1 74 0.27 g dividing these two numbers and multiplying by 100 to change it to a percent. Give me 44.87 percent potassium in this compound. My final step, then, is I want to find out of those 57.4 g. How many grams of potassium Well, I know it's 44.87% so I need to multiply. To find that answer, I'm going to write that percent. Bacca's a decimal. In other words, move the decimal two places to the left to right, 44.87% as a decimal. And then I'm going to multiply that by the original mass of the compound, which was 57 0.4 g. This tells me that I have 25 0.8 g of potassium in this compound. So of that original, 57.4 g of the compound, 25.8 g were due to the potassium. Thanks so much. Have a great day.

We see that the density of calcium is almost twice as much as potassium. However, the massive potassium is only slightly less than a massive calcium. So let's provide a nanoscale explanation. So density the density of a substance. Mhm. Is the property that describes, Yeah. Yeah. The mass per unit volume of a substance. Yeah. Yeah. It is directly related to the mass and inversely related to the volume. Yeah. The calcium atoms possess a smaller radius. Yeah. Uh huh. Mhm. Yeah. As compared to the potassium atoms. Yeah. Mhm. Yeah. Therefore unpacking. Yeah. Mhm mm acquire less volume as they require less volume or they acquire less volume. Yeah, they have a higher density. As explained previously that density is inversely proportional two volumes.