The product of (wavelength) times (frequency) is always the same number ...
the speed of the wave in whatever material it's traveling through. So if the
frequency is increased, then the wavelength must <em><u>de</u></em>crease by the same
factor, in order to keep the product the same.
Calculate mass of lead:
1.00 cm3 lead x 11.4 g/cm3 = 11.4 g lead on one side of balance
To balance that, one needs 11.4 g of iron on the other pan. Calculate volume of iron to give you 11.4 g:
11.4 g iron x 1 cm3/7.87 g = 1.45 cm3 of iron needed
Brain list please
The atomic number is the number of protons. So, you can subtract the atomic number from the mass number to find the number of neutrons.
I hope this helps! :)