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Chemistry

GCSE

What is an isotope?

Atoms of the same element with different numbers of neutrons

Answered by Bella S. • Chemistry tutor

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How many moles are in 6g of carbon?

moles = mass/mrn = 6/12n= 0.5

Answered by Lucy O. • Chemistry tutor

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Magnesium reacts with hydrochloric acid to form a salt. What volume of 0.2dm(-3) HCL is required to react with 4g of Magnesium? Give answer in cm(3).

First draw out the equation. Mg + HCL = MgCl₂ + H₂Now balance this equation Mg + 2HCl = MgCl₂+ H₂Next we need to work out the moles of Mg. We know that we have...

Answered by Katie C. • Chemistry tutor

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In the flowing equitation 2H2+O2→2H2O how many grams of oxygen are needed to make 9g of water?

2H₂+O₂->2H₂OThe best way to answer any mass balancing questions like this is to set the information in a table as follows and fill in the blanks: 2H₂+ O

Answered by Caroline O. • Chemistry tutor

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Describe how elements are arranged in the periodic table

Elements in the periodic table are arranged in order of increasing atomic (proton) number. Elements with the same number of electron shells are arranged in the horizontal rows (periods), and elements with...

Answered by Georgia C. • Chemistry tutor

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