substance is matter of particular or definite chemical constitution ex: iron, methane
mixture are two or more substances that have been combined to retain their individual chemical characteristics ex: salt water, cola
Answer:
Neutral atoms can be turned into positively charged ions by removing one or more electrons.
Explanation:
If there is an atom that has 9 protons and 9 electrons, removing an electron from the atom will gain a postive charge.
Answer: 
will have a greater partial charge.
Explanation:
A polar covalent bond is defined as the bond which is formed when there is a low difference of electronegativities between the atoms, thus resulting in charge difference. Example:
Non-polar covalent bond is defined as the bond which is formed when there is no difference of electronegativities between the atoms and thus there is no charge difference. Example: 
Ionic bond is formed when there is complete transfer of electron from a highly electropositive metal to a highly electronegative non metal. The electronegative difference between the elements is high. The charges on cation and anion neutralise each other. Example: 
Thus as will have greater partial charge.
D. breakdown of rocks through mechanicals or chemicals processes
Explanation:
In order to go from mass of magnesium to atoms of magnesium, we have to do two things:
Convert mass of Mg to moles of Mg using the molar mass of Mg as a conversion factor
Convert moles of Mg to atoms of Mg using Avogadro's number (6.02×1023) as a conversion factor
Step 1:
Before we start, I should note that the molar mass of Mg is 24.31gmol. We can go from mass to moles using dimensional analysis. The key to dimensional analysis is understanding that the units that you don't need any more cancel out, leaving the units that are desired:
48.60g
×1mol24.31g
=2.00mol
Step 2:
We'll use this relationship:
www.sprinklernewz.uswww.sprinklernewz.us
Using the moles of Mg that we just obtained, we can use Avogrado's number to perform dimensional analysis in order to cancel out units of mol to end up with atoms of Mg:
2.00mol
×6.02×1023atoms1mol
=1.204×1024atoms
Thus, 48.60g of Mg is equivalent to 1.204×1024atoms
Hope this helped :)
