chemical changes occur when a substance combines with another to form a new substance called chemical synthesis or alternatively chemical decomposition into two or more different substances these processes are called chemical reactions and in general are not reversible except by further chemical reactions
A. Atoms only. An element cannot be separated into simpler materials
Answer:
The ppm carbon in the seawater is 104.01.
Explanation:
Mass of seawater = 6.234 g
Mass of carbon dioxide gas produced = 2.378 mg = 0.002378 g
1 mg = 0.001 g
Moles of carbon dioxide gas = 
1 mol of carbon dioxde gas has 1 mole pf carbon atoms,then 
will have ;
of carbon
Mass of of carbon ;
To calculate the ppm of oxygen in sea water, we use the equation:
(Both the masses are in grams)
The ppm carbon in the seawater is 104.01.
Avagadro's number is just a measurement. One mole is 6.022 X 10^23 of anything - atoms, molecules, marbles... anything.
<span>1) If one mole = 6.022 X 10^23, then 8.00mol of H2S is: </span>
<span>(3.00mol H2S) (6.022 X 10^23 molecules H2S / 1 mol H2S) = 1.8060 X 10^24 molecules H2S. </span>
<span>Rounded to 3 sig figs =1.81 X 10^24 molecules H2S
</span>part2.
<span> This one uses moles in the stoichiometric sense as well as the measurement. One formula unit of MgCl2 contains 1 mole Mg and 2 moles Cl. </span>
<span>First, figure out how many moles of formula units there are. </span>
(1.81 X 10^24 FU's) (1mol MgCl2 / 6.022 X 10^23 FU's) = 3.0056mol MgCl2.
<span>Now, we know that there are 2 moles of Cl in every mole of MgCl2 (2 Cl atoms in every unit of MgCl2). From this we can determine how many moles of Cl atoms there are: </span>
<span>(3.0056mol MgCl2) (2mol Cl atoms / 1mol MgCl2) = 6.0112mol Cl atoms. </span>
<span>Now round to 3 sig figs = 10.0mol Cl atoms</span>
Moles= mass/Mr
Moles= 3.82/40
Moles= 0.0955 mol
