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Calculate the relative molecular mass of CaCO3. (relative atomic mass (Ar): C= 12, Ca= 40, O= 16)

Number of atoms Ca x1 => 40x 1= 40 C x 1 => 12x1 = 12 O x 3= 16 x 3= 48CaCO3 RMM= 40 + 12 + 48= 100
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Answered by Roxanne M. • Chemistry tutor
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How do you form the passé composée?

The past tense known as the passé composée in French is composed of three parts. The subject (je), the auxiliary verb (a conjugated form of with avoid or être) and finally the past participle (mangé).Avoir a...
KD
Answered by Katharine D. • French tutor
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How can we really know what the past was like?

Historians can never truly know what the past was like. This is why historians have different interpretations of the past and how it occurred. Having said this, historians can still form a detailed and compr...
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Answered by Angus R. • History tutor
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Solve algebraically the simulations equations: x^2+y^2=25 and y-3x=13

x 2 +y 2 =25; y-3x=13; x 2 +(13+3x) 2 =25; x 2 +9x 2 +78x+169=25; 10x 2 +78x+144=0; 5x 2 +39x+72=0; (5x+24)(x+3)=0; x=-24/5 and y=-7/5;x=-3 and y=4
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Answered by Nadia C. • Maths tutor
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How do I balance an equation for a reaction, such as complete combustion of ethene?

Balancing equations is a simple conservation of the elements in a reaction: what you start with is what you finish with. With that in mind, let's take a look at the equation:C 2 H 4 + O 2 -> CO 2 + H 2 OT...
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Answered by Kieran M. • Science tutor
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