Help Zone

HumbleArmadillo3023

Hello.

I have just learned about transmission mechanisms and I am not sure I understand the difference between motor, driven, and intermediate transmission mechanisms.

Also, I do not understand how the direction of a rotation can change or not, and how some systems are reversible and others not.

Can you give me some examples? Thank you :)

HumbleArmadillo3023

How do I calculate the volume of solvent to add in a dilution? I am given an initial concentration (0.25 g / L), the volume (14 ml) and I want the final concentration (0.20 g / L).

Usually, I would use c1 * V1 = C2 * v2 to find the final volume, but I don't know which volume to add.

Can you help me?? Thank you

ShyMoon4957

How do we compare different solutions according to their concentration?

ShyMoon4957

Hello! I have a homework assignment on dilution and I have 3 questions

1) What is the difference between a dissolution and a dilution?

2) Does a dilution always lower the concentration?

3) My homework says that my final solution has a volume of 100ml and a concentration of 0.24g / ml, then the initial solution has a volume of 75ml. How do I find the initial concentration ??

Thanks in advance :)))

ShyMoon4957

Hello!

In my homework, it requires converting a 77 g / ml concentration into a mass volume percentage, but I don't know how.

Thanks for your help in advance!

ShyMoon4957

Good evening,

Can you show me how to solve a complete dilution problem? I have a lot of difficulty with that.

ShyMoon4957

Hello? I am lost here, is a colloid a heterogeneous or homogeneous mixture? Thank you

ShyMoon4957

Hello! Can you give me concrete examples of the different mixtures? (heterogeneous, homogeneous)

Thank you!

FastFox1311

Hello,

I can't quite understand the concept of solubility, could you please explain it to me?

Thanks a lot!

FastFox1311

Hello,

I can't quite understand the solutions and the difference between solute and solvent. Could you explain it to me, please?

Thanks a lot!

ShyMoon4957

Someone throws a huge 300 kg object into a 40,000 L swimming pool without any splashes being produced. The pool’s volume is measured afterwards, thus showing that it reaches 45,000 L. What is the density of the object? Help !?!

FastFox1311

Hello! Must I measure a solid with a ruler to determine its density ? I no longer remember :(

SweetCrocodile1896

Hi, how come oil floats on the water? Thank you for explaining this to me 🙂

SweetCrocodile1896

Hi!

What causes one substance to have a higher density than another? thank you

SweetCrocodile1896

Hello,

I have to find the density of a solid for my science lab, but don't know how to do it. Can you explain me how, please?

Thanks a lot!

SweetCrocodile1896

Hi! I have a lab this week on the density of gases, liquids, and solids.

I understand that for the liquids I can weigh and measure the volume, but I have two questions:

1) how do I measure the mass of a gas?

2) how do I measure the volume of a solid?

thanks in advance :))

SweetCrocodile1896

Are all the material properties advantageous? For example, why is fragility an advantage?

QuietDragon2728

Hello,

I can't seem to understand how energy can manifest naturally. Can you explain to me how it manifests please?

Thanks a lot!

QuietDragon2728

Hello,

I can't figure out what the motion transfer mechanisms are used for and what the mechanisms are. Can you help me please!

Thanks a lot!

QuietDragon2728

Hello,

Can you explain how to use the periodic table please? I can’t use it correctly.

Thanks a lot!

QuietDragon2728

Hi,

I'm not sure why not all atoms are molecules (and why molecules aren’t necessarily atoms)? Also, what is the difference between a molecule and a composite substance?

Thanks

QuietDragon2728

How do you know if a particle is an atom or a molecule?I'm not sure I understand...

QuietDragon2728

Hello,

In my assignment I have to differentiate the atoms from molecules and the elements from compounds, but I can't do it. Can you explain to me how I can tell them apart?

Thank you so much!

ZenZombie9054

What is the difference between a force, a constraint, and the consequences of the effects of a force?

ZenZombie9054

Hey,

What's the difference between linkage and guiding?

QuietDragon2728

What constitutes and doesn’t constitute a color change in a chemical reaction?

AdorableMoose4991

Good morning! I have a hard time distinguishing the lithosphere, the continental lithosphere, the oceanic lithosphere, landforms and the natural resources of the lithosphere. Can you help me?

AdorableMoose4991

hi! What distinguishes the biosphere, hydrosphere, lithosphere, and atmosphere?

AdorableMoose4991

Good morning!

How do you tell plant and animal cells apart with a microscope? Thank you!

AdorableMoose4991

Hello! I have a hard time using the microscope. Can you explain how to use it and give me some advice?

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