<span>A. Exact ecological footprints are often difficult to calculate, but estimates can be useful in comparing populations.
</span>Which of the following could be said about ecological footprints? <u /> <u>Exact ecological footprints are often difficult to calculate, but estimates can be useful in comparing populations.</u><u />
NOT: b. Ecological footprints can't be used to determine carrying capacity. C. Ecological footprints don't take into account resources needed to absorb and manage wastes. <span>D. The average ecological footprints for various countries are nearly identical.</span>
Answer is: there is 2,69·10²³ atoms of bromine. m(CH₂Br₂) = 39,0 g. n(CH₂Br₂) = m(CH₂Br₂) ÷ M(CH₂Br₂). n(CH₂Br₂) = 39 g ÷ 173,83 g/mol. n(CH₂Br₂) = 0,224 mol. In one molecule of CH₂Br₂, there is two bromine atoms, so: n(CH₂Br₂) : n(Br) = 1 : 2. n(Br) = 0,448 mol. N(Br) = n(Br) · Na. N(Br) = 0,448 mol · 6,022·10²³ 1/mol. n(Br) = 2,69·10²³.
