Chemistry, 29.08.2019 21:30 boi1234520

Why do scientists sometimes discard theories?
select one:
a
the steps in the scientific method were not followed in order.
b
public opinion disagrees with the theory.
c
the theory is opposed by the church.
d
contradictory observations are found.
e
congress voted against it.

Answers: 2

Show answers

Answers

Answer from: samone26

d . Contradictory observations are found.

Explanation:

A scientific theory can be define as the proposed explanation of cause of a natural phenomena or event. It is based upon evidences obtain from direct observations and experimental procedures.

A change in the concept of the scientific theory only occurs when there exists a contradictory idea or evidence by the other experimenters which explain the facts which are required to discard the theories.

Answer from: Quest

1. 1 mole of anything contains 6.022x10^23 pieces

2. a

3. c, number

5. 1.24x10^24atoms / 6.022x10^23atoms/mole = 2moles h2 atoms

6. fe2br3 mass = 2moles x mass fe + 3 moles x mass br

molar mass = grams / number of moles = g/mole

to find moles = g / molar mass

to find mass = g = molar mass / moles

Answer from: Quest

Answerthis solution will not form a precipitateexplanationsolubility equilbrium: pbf₂(s) ⇄ pb²⁺(aq) + 2 f⁻(aq)the solubility product expression is $k_{sp} = [\text{pb}^{2+}][\text{f}^- ]^2 = 4 \times 10^{-8}$ (we exclude solids from the equilibrium expression).now suppose we have the trial ion product q, which we can define as $q = [\text{pb}^{2+}]_{\text{initial}} \cdot [\text{f}^- ]^2_{\text{initial}}$ then, we can interpret q as the product of the concentration of the ions that we have and ksp as the product of the ion concentrations that are needed to form a saturated solution.if q > ksp, then that implies that there will be a surplus of ions that exceed the amount that is required to form a saturated solution. a precipitate will then form (the precipitate continually forms until the surplus ions are removed and q is decreased to ksp's value).if q = ksp, the saturated solution that forms is barely saturated and the precipitate will be minimal.if q < ksp, then the ion concentration will not be enough to form a saturated solution (so no precipitate).using our information, we calculate the trial ion product: $\begin{aligned} q & = [\text{pb}^{2+}]_{\text{initial}} \cdot [\text{f}^- ]^2_{\text{initial}} \\ & = (1.9 \times 10^{-3} ) (3.8\times 10^{3})^2 \\ & = 2.7 \times 10^{-8} \end{aligned}$ since q = 2.7 × 10⁻⁸ < ksp = 4 × 10⁻⁸, a precipitate will not form.