For the first question:
Valuable ore deposits and gem crystals are often associated
with igneous intrusions. So for this question the correct option is option “d”.
An example like the Pegmatite’s, which are a form of igneous intrusions, is
responsible for the creation of variety of gems like topaz and tourmaline.
For the second question:
For this specific question, option “c” seems to be the
correct option. Weathering, deposition, compaction, cementation are the
possible sequence that leads to the formation of sedimentary rocks.
Answer:
Anemometer. An anemometer is a type of weather instrument that measures wind speed.
The rate of the reaction is measurable quantity that refers to the amount or how much is are chemical substances reagents used up or converted into the product over some period of time.
Rate = change in the amount/time.
This can indirectly be observed through many ways, such as the volume of gas given off if the byproduct is a gas being produced, the colour of the solution etc.
A, I believe it is 810liters of oxygen! Please correct me if im wrong
Answer:
The pressure of the gas increased (if temperature remained constant).
The Boyle's law supports this observation.
Explanation:
The initial measurements of the gas are given as;
volume = 100 L
Pressure = 300 kpa
The second measurement is given as;
Volume = 75 L
The second reading implies that the volume of the gas has decreased. If the temperature of the gas remained constant, then the pressure must have increased according to the Boyle's law;
At constant temperature, the pressure of a given mass of an ideal gas is inversely proportional to its volume.