Question 596205
1.Is mass a measure of Earth's gravitational pull on matter? 


No, mass is the measure of the amount of stuff/substance an object has (there's a lot more to it, but this is the basic idea).


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2.Isotopes are atoms of the same element that have different masses.


This is true as isotopes have the same number of protons (which means you're dealing with the same element), but have different amounts of neutrons (which leads to different masses)


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3.The relationship between the mass m of a material, its volume V, and its density D is D=m/V.


You are correct.


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4.A positively charged particle with mass 1.673 x 10–24 g is a proton. 


You are correct.