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What is the relative formula mass of sodium chloride?

58.5

Relative formula mass (Mr) is found by adding together the relative atomic masses (Ar) of all the atoms present in a compound. 

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Answered by Jenny S. Chemistry tutor
60728 Views

Providing reasoning, what is the trend in the atomic radius of row 3 elements across the periodic table?

Decreasing atomic radius across the periodic table.

- greater number of protons in the nucleus resulting in a greater nuclear charge.

- little/no change in ...

JS
Answered by Jenny S. Chemistry tutor
4397 Views

Why are alkanes saturated and alkenes unsaturated?

Alkanes are saturated because they contain only single covalent bonds. Alkenes are unsaturated because they do have double covalent bonds.

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Answered by Calum M. Chemistry tutor
17037 Views

Why do the muscles of the Iris contract and relax?

To alter the size of the pupil, so the correct intensity of light is allowed through. Enough light is let through to allow clear vision, but not so much light that the retina might become damaged.

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CM
Answered by Calum M. Biology tutor
8861 Views

Which state can a substance NOT be in if heat transfer through convection is occurring?

Solid.

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Answered by Calum M. Physics tutor
3492 Views

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