Scientists use models to show the characteristics of compounds. Of the different models,ball-and-stick model and space-filling model are commonly used but similar. Ball-and- stick model shows the bond between both atom and not the relative size of the atoms. Space-filling model shows the relative size of the atom and not the bond between the atoms. Both are 3-Dimensional and use color spheres within the model.
Answer:
1 mole of atom is correct.
B. A chemical change has occurred and energy was given off
If iron has a density of 7.87g/cm³ and a mass of 3.729g, then the volume of iron is 0.474cm³
HOW TO CALCULATE VOLUME:
- The volume of a substance can be calculated by dividing the mass by its density. That is;
Volume (mL) = mass (g) ÷ density (g/mL)
- The density of iron is given as 7.87g/cm³ while its mass is 3.729g of iron. Hence, the volume can be calculated as follows:
Volume = 3.729 ÷ 7.87
Volume = 0.474cm³
Therefore, the volume of iron is 0.474cm³
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1) Calcium carbonate contains 40.0% calcium by weight.
M(CaCO₃)=100.1 g/mol
M(Ca)=40.1 g/mol
w(Ca)=40.1/100.1=0.400 (40.0%)!
2) Mass fraction of this is excessive data.
3) The solution is:
m(Ca)=1.2 g
m(CaCO₃)=M(CaCO₃)*m(Ca)/M(Ca)
m(CaCO₃)=100.1g/mol*1.2g/40.1g/mol=3.0 g