Sodium has a mass number of 23amu. Since sodium has 11 protons, the number of neutrons must be 23 – 11 = 12 neutrons.
Answer:

Explanation:
First, find the molar mass of calcium (Ca). This can be found on the Periodic Table.
Next, find the number of moles.
Avogadro's Number tells us the number of atoms in one mole.
Therefore, there are 6.023*10²³ atoms in 1 mole.
We have 6.023*10²³ atoms of calcium, so it must also be 1 mole of calcium.
Finally, find the mass. Set up a proportion using the molar mass of calcium.

Multiply. The moles (mol Ca) will cancel.


There are <u>40.08 grams </u>in 6.023*10²³ atoms of calcium.
Answer:
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Weight of any object is given as follows:
Weight = mass*acceleration due to gravity
The unit of weight is N, while the unit of mass if kg.
In the given statement the unit is kg means the correct statement is this rock mass is 8 kilo-grams
<span>I believe that in this
case the controlled parameter is the type of animal that they are observing.
There are a lot of animals in the ocean, therefore to have a scope of their
study of observation, they are controlling or limiting their observations on
the whale alone. Hence the controlled parameter is the type of animals, whales.</span>