1) d
2) b because the independent variable is the thing you change/control in an experiment
3) c because the dependent variable is the thing being measured in an experiment
4)hmm it might be d, as c and a are both correct as different sized feeders would make it an unfair test and different types of food would as well
5) c
6) a
7) b obviously because if he activated them at different times then the ones activated last would have an advantage
Answer:
La masa atómica del hierro es 55.847 gramos por mol.
Explanation:
Las masas molares de 
, 
, 
y 
son 53.940 gramos por mol, 55.935 gramos por mol, 56.935 gramos por mol y 57.933 gramos por mol, respectivamente. La masa atómica del hierro se determina mediante el siguiente promedio ponderado:
La masa atómica del hierro es 55.847 gramos por mol.
