## Units

Science questions not covered in Chem 14A and 14B. Try to limit questions to chemistry (inorganic chemistry, physical chemistry, organic chemistry, biophysical chemistry, biochemistry, materials science, environmental chemistry).

ariaterango_1A
Posts: 57
Joined: Wed Sep 18, 2019 12:15 am

### Units

I'm having trouble with units when conducting some of these problems. Could anyone help me with the units of velocity, threshold energy, Plank's constant, and frequency?

Reina Robles 2B
Posts: 71
Joined: Fri Aug 09, 2019 12:16 am

### Re: Units

Velocity: meters per second
Threshold energy: Joules
Plank's constant: Joules times seconds
Frequency: Hz (which is also cycles per second)

You can also find these on the constants and equations sheet that they give us during tests:
https://lavelle.chem.ucla.edu/wp-conten ... ations.pdf

I hope this helps!

Rebecca Remple 1C
Posts: 137
Joined: Wed Sep 18, 2019 12:16 am
Been upvoted: 1 time

### Re: Units

Reina Robles 1H wrote:Velocity: meters per second
Threshold energy: Joules
Plank's constant: Joules times seconds
Frequency: Hz (which is also cycles per second)

You can also find these on the constants and equations sheet that they give us during tests:
https://lavelle.chem.ucla.edu/wp-conten ... ations.pdf

I hope this helps!

I completely agree with Reina's advice! Also, I highly recommend using the constants and equations sheet while solving homework problems to simulate a test situation. Additionally, I wanted to note that 1 Joule is equivalent to 1 kg⋅m2⋅s−2. This can help you cancel units, depending on what you're solving for. This conversion used to trip me up and it shows up a lot in the homework problems. I hope this helps!

-Rebecca

Tiffany Chao 2H
Posts: 117
Joined: Fri Aug 09, 2019 12:17 am

### Re: Units

velocity: m/s
threshold energy: J or kg. m^2. s^-2
Planck's constant: 6.626 x 10^-34 Js or kg.m^2. s^-1
frequency: Hz or s^-1

ariaterango_1A
Posts: 57
Joined: Wed Sep 18, 2019 12:15 am

### Re: Units

Thank you everyone! I didn't realize we would be provided a list of constants. It would be a good idea for me to do the practice problems with this sheet to cancel out units.