There are currently two hydrogen cars available to buy in the UK – the Toyota Mirai, which has been around for 10 years, and ...

of~an~element} = \frac{mass~of~an~element~in~the~compound}{relative~formula~mass~M_r} \times 100\) There are six atoms of hydrogen in the compound, so the mass of hydrogen is 6 × 1 = 6.

The symbol for magnesium is Mg, and sulfuric acid is a compound containing sulfur, oxygen, and hydrogen. Its formula is written: H2SO4. So we write Mg plus H2SO4. An arrow shows the direction of ...