Scientists observe the world around them, from which to draw questions. Their predictions as to the answer are what we call a “hypothesis”. Thus, a scientist’s job is to answer the very hypotheses that they and their piers come up with.
Answer:
Carbon-14 has a half life of 5730 years. This means it takes 5730 years for half of the carbon-14 atoms to decay to carbon-12 in a given sample (eg: 100 carbon-14, one half life = 50 carbon-14, 50 carbon-12).
Explanation:
Missing question:<span> How many grams of oxygen are needed for complete combustion of the toluene?
Chemical reaction: </span>C₇H₈ + 9O₂ → 7CO₂ + 4H₂<span>O.
V(</span>C₇H₈) = 8,30 ml.
d(C₇H₈) = 0,867 g/ml.
n(C₇H₈) = V(C₇H₈) · d(C₇H₈).
m(C₇H₈) = 8,3 ml · 0,867 g/ml.
m(C₇H₈) = 7,19 g.
n(C₇H₈) = m(C₇H₈) ÷ M(C₇H₈).
n(C₇H₈) = 7,19 g ÷ 92,14 g/mol = 0,078 mol.
From chemical reaction: n(C₇H₈) : n(O₂) = 1 : 9.
n(O₂) = 9 · 0,078 mol = 0,702 mol.
m(O₂) = 0,702 mol · 32 g/mol = 22,5 g.
Answer: 2hqu
Explanation: because you have to add them
