Some one help me with this the highlighted one is the problem

Atomic proton number
atomic mass number
atomic symbol
periodic table
groups
8
periods
7
amphoteric line
transition metals
non-metals
other metals
bromine
dull
electricity
magnets

Ibelieve 4mn because it’s like you’re combining them

the law of definite proportions states samples of a compound will always contain the same proportion of elements by mass. in other words, a given compound will always contain the same elements in the same proportions by mass.the law of multiple proportions states when two elements combine with each other to form more than one compound, then the weights of one element that combine with a fixed weight of the other are in a ratio of small whole numbers.