Answer:
When manganese(IV) oxide is added to hydrogen peroxide, bubbles of oxygen are given off. To make oxygen in the laboratory, hydrogen peroxide is poured into a conical flask containing some manganese(IV) oxide. The gas produced is collected in an upside-down gas jar filled with water.
The correct option is C. Nitrogen gas has the highest percentage by volume of all the gases that make up the air.
The composition of the air is as follows:
nitrogen = 78.09%
Oxygen = 20.95%
Argon = 0.93%
Carbon dioxide = 0.04%
water vapour = traces amount.
The answers are A. Pseudoscience is often based only on opinions; D. Pseudoscience often involves explanations of beliefs; E. Pseudoscience includes subjective ideas.
Explanation:
Pseudosciences comprises disciplines or theories that do not follow scientific standards but claim to be factual. This includes areas such as clairvoyance or astrology because this is not based on evidence but subjectivity. Indeed, the base of most pseudosciences are personal beliefs, opinions, or subjective ideas. Moreover, complex theories or methods are created to try to explain these beliefs, but because they do not follow scientific standards they are not considered as valid. In this context, options A, D, and E are correct.
Answer:

Explanation:
Given
31.8 moles of water
Required
Determine the number of molecule
In standard units: 1 molecule of water is:

Multiply both sides by 31.8



Express 191.4996 as a standard form

Apply law of indices:


Approximate:

When struck, the mineral is tested for lattice type. Depending on how it shatters, scientists can determine how the mineral forms on the atomic level by noting the molecular weaknesses of the system. These weaknesses are the points at which the mineral breaks along.
Depending on the type of hammer, they could also be testing the tensile strength and, even possibly, the hardness, depending on the angle of the blow. How hard the rock can be hit without breaking is the TS, and whether or not the mineral is scratched by the hammer is the hardness.