What properties would have caused early researchers to name hydrogen "inflammable air”

It ignited in air to form water

Explanation:

In the experiments of Cavendish, he discovered a gas lighter than air when he added certain metals to dilute acids. The gas when breathed is significantly different from air.

The gas is known to burn in air when it approaches a flame to form water hence the name 'inflammable air' was given to the gas. It was later called hydrogen which means 'water former'.

2fe + 3h2so4 -> fe2(so4)3 + 3h2

it is necessary to balance equations in order to get the proper amount of reactants as well as products in order not to make a miscalculation.

you cannot change the subscripts as that would change the substance itself. for instance, diatomic elements such as h2 only have the subscript two when a gas. another example would be so4, if you were to change the subscript, the element would no longer be sulfate.

we change the coefficients instead as that only changes the number of molecules rather than the substance itself.

hope this !

the density of gold = 19.3 g/cm3

the relation between density and mass and volume is

density = mass / volume

given :

mass of gold = 13 g

density = 13g / volume = 19.3

volume = 13 /19.3 = 0.67 cm^3

thus volume of gold nugget = 0.67 cm^3