(free points) is a subatomic particle of an atom the smallest unit of matter? or is and atom the smallest part of matter?

subatomic matter is not the smallest unit of matter, but its definetely smaller than atom. fernions which form subatomic particles is the smallest unit of matter.

An atom is the smallest unit of matter. It is the smallest component of an element that still has the properties of that element. Atoms are made of three particles. protons, neutrons, and electrons.

"you start with 15.67 g mgco3-xh2o, when heated and all the water is removed, you are left with 7.58 g mgco3 only.

therefore, you had 15.67 - 7.58 = 8.09g h2o  

moles of each :

7.58g mgco3 = ? moles = 7.58g / 83.4g/mole = 0.09moles  

8 09g h2o = ? moles = 8.09g / 18g/mole = 0.44moles  

molar ratio between the two by dividing both numbers by the smallest number :

0.09 / 0.09 = 1  

0.44 / 0.09 = 4.8  

mgco3-5h2o"