HEY THERE
THATS EASY...
YOU CAN USE A MAGNET TO ATTRACT THE IRON FILLINGS WHICH WOULD THEN SEPARATE FROM THE SAND.
The answer is electron.
The nucleus of a neutral potassium atom is "surrounded" by electron.
The neutral potassium atom contains equal number of protons and neutrons, and there are 19 electrons and 19 protons while 20 neutrons.
20 protons and 20 neutrons are there in the nucleus while 19 electrons surrounds the nucleus in different orbits .
Answer:

Explanation:
Hello,
In this case, since the undergoing chemical reaction is:

The corresponding moles of carbon dioxide occupying 40.0 mL (0.0400 L) are computed by using the ideal gas equation at 273.15 K and 1.00 atm (STP) as follows:

Then, since the mole ratio between carbon dioxide and calcium carbonate is 1:1 and the molar mass of the reactant is 100 g/mol, the mass that yields such volume turns out:

Regards.