Hi there, good question. When we 'borrow' 10 from the 3, we're actually recognizing place value: the 3 represents 30 (since it's in the tens place), so borrowing 10 leaves 20, and we add the borrowed 10 to the 2 in 32.5, making it 12. This makes the subtraction 12.5 - 5, giving a remainder of 7.5. It's a method to simplify the process while respecting place values.

Hello there. The first number was 382. We were able to round this number to "400" because we were rounding to the nearest "hundred." This means we have to look at the values in the "tens"place when making our decision. If the number in the "tens" place is 5 or greater we round the number in the "hundreds" place up by one. In this case, it goes to "400." Good question.

Ha ha. True that, we wouldn't want to invent random new compounds and disrupt the balance of the universal timeline.

😂

I'll work on some for you.

Welcome 👍

Hello, thanks for your question. The reason the coefficient before the CaCO3 is a "1" is because we are counting atoms. On the left side there is only one Ca atom, the same on the left side. Also, the "CO3" on the left side has one carbon and three Oxygens, we can only have one Carbon and three oxygens on the right side as well. The only combination of coefficients that allows for the same number of Ca, C, and O on both sides is 1, 1, 1. Hope this helps.

Glad the videos were help to you. Hope your test went well.

Hey bro I'm also rushing one night before exam but idk how does H2+ O2= H20 happens have you got any tutorial for that?

@@Shadow12447did u find out why

@@pamer8345 still dunno but I guess it has something to do with valency atomic no. And atomic mass

What is happening is that Hydrogen gas (H2) and Oxygen gas (O2) have covalent bonds between the atoms and these bonds are broken in a combustion reaction. The atoms are then free to rearrange and bond with others, such as one Hydrogen can form bonds with two oxygen atoms. The ratio of 2:1 between hydrogen and oxygen occurs because this satisfies the bonding requirements, think "octet" of each atom, resulting in the formation of water (H₂O).

Its m, he just made a mistake, he said so in a reply

Thank you. Glad our videos have been helpful to you.

You're welcome. Keep Learning, we will be here to help.

Use m

Hello, the unit is "m." the Hertz unit of "hz" was written inadvertently. Thanks for highlighting this, we will update the video.

Did not know I sounded like an American President. I'll take the comment in a positive way. In either case, glad I could help with the videos. Happy Learning.

Hi there. You can take Hydrogen gas and add it to Oxygen gas to make water. 2H2 + O2 --> 2H2O. You can also take a strip of Magnesium ribbon and allow it to react with oxygen to form Magnesium Oxide. You have to apply head to get the reaction to go, but once it goes it will be a bit dangerous. Caution with this reaction as the temperature of the reaction can be quite high and you can get burned. Also, you will need to use a cobalt glass to protect your eyes as the resulting during magnesium will be very bright and can harm your eyes. (URGENT) Do not look at the flame directly without the use of a cobalt glass shield. Please take extreme caution to avoid harm to yourself, your eyes, or others that may be in the vicinity, they should use cobalt glasses too if they will be looking at the bright flame.

I'm sorry the process was not shown for you. I'll generate another example and include it for your consideration. Thanks for letting me know.

You are most welcome

Hello there. Assuming the list is an array, I think you can just do a for loop for every item in the array and print out the array name while implementing the "upper()" function. in the loop as follows... names = ["carl", "mary", "jane", "suki"] nameUpper = [item.upper() for item in names] print(nameUpper) This should result in the following: ['CARL', 'MARY', 'JANE', 'SUKI']

Glad it helped!

Hi there. Sorry to hear the content was hard. How can I help make it easier to understand for you?

Hello ZM, thanks for the question. At first glance the units of "J" for the stated frequency should be "hz" for hertz. Given this change, to calculate the wavelength, we take the speed of light (3.0E8 m/s) and divide it by the stated frequency (4.909E-19 Hz). This should give you a wavelength of 6.11E26 meters. Happy Learning!

Glad it was helpful!

You're welcome! Glad we could help. Happy Learning.

Hello, it depends on what information is given to you. You can find the [H=] from other information such as the pOH, or the [OH-]. In the case of pOH provided, recall pH + pOH = 14, just subtract the pOH form 14 and you will know the pH. Once you have this you can then enter the pH value in the following: [H+] = 1x10 ^ -pH. if [OH-] is you can plug the value into pOH = -log [OH-] to get the pOH value and then you can subtract that value from 14 to get the pH. At this point, follow the same steps outlined above for pH to get the [H+]. ~Happy Learning.

You are very welcome. Glad we could help. Happy Learning.

Hello, You would use the C = wavelength * freq equation. Derive the new equation for freq (f = C / wavelength), plug the values in and your freq. should be 1E6 hz.

Hello Jm, use the equation "C= wavelength * frequency." Divide C by the frequency and you should get "3.0E8 / 3.0 E9" which is 1.0E-1 wavelength.

You're welcome. Glad you could learn with us. See you in the next video.

Hello, Kw is the equilibrium constant for water and has a value of 1.0 x 10E-14.

Thanks for the feedback.

Hello, the reason water is able to do this is because water can engage in a single proton exchange with another water molecule. When this occurs, the acid (H3O+) and (OH-) ions products are formed. They in turn react with each other to reform water as H2O. This reaction is reversible and occurs with the same rate as the forward reaction to form the ions. Keep watching and keep learning.

Thank you for the question. In step 3, I distributed the P1V1 across to V1. This results in P1V1V1 in the numerator, with only two copies of V1.

Hello there. The simple answer is that once water takes one proton it forms hydronium (H3O) and it has a positive charge. Any other proton that potentially could bind won't actually bind because there are would be high repulsive forces between the positive charged hydronium and the positive proton.

You’re welcome 😊

Hello Zina, Thanks for your question. I'll make a video explaining this for you. For now, here is the quick explanation. The short answer is this...take the negative value of the pH and plug it into this equation: [H+] = 1x10 (raised to -3.78). A bit longer explanation is this...Remember the pH equation is: pH=-log[H+]. Plug in the value of the pH value you gave me and you get, 3.78=-log[H+]. We want to then multiply both sides by (-1), this gives you -3.78= log[H+]. Now take each side of the equation and set it as the exponent as you raise each side to (1x10). On the left you will get: 1x10 (exp -3.78) and the left will cause the "1x10" to cancel with the "log" leaving the [H+] behind. The new equation is is the new concentration of your hydrogen ions. Hope that helps happy learning.

Zina, I've added a video lesson on how to solve this problem for you and others to review. You can check it out at the following URL: kzbin.info/www/bejne/d4m7aGuVfrmZjqM

@@ScienceBeetle thank u, i'll check it out

Its okay, we are happy to help as much as we can. Keep watching, learning and see you soon. Blessings!