Chemistry for Biologists: Some basic chemistry
Some basic chemistry
Living organisms and chemistry
Biology is about living things - organisms. All living organisms are made of chemicals. To understand biological substances and the changes that take place in living organisms you need a good knowledge of the underlying chemistry. We will build up a picture of the chemicals that make up living organisms by starting small and getting bigger.
The starting point is atoms - the building blocks of all matter. We will then look at how these come together to make elements and compounds.
Answer:
3141N or 3.1 ×10³N to 2 significant figures. The can experiences this inward force on its outer surface.
Explanation:
The atmospheric pressure acts on the outer surface of the can. In order to calculate this inward force we need to know the total surface area of the can available to the air outside the can. Since the can is a cylinder with a total surface area given by 2πrh + 2πr² =
A = 2πr(r + h)
Where h = height of the can = 12cm
r = radius of the can = 6.5cm/2 = 3.25cm
r = diameter /2
A = 2π×3.25 ×(3.25 + 12) = 311.4cm² = 311.4 ×10-⁴ = 0.031m²
Atmospheric pressure, P = 101325Pa = 101325 N/m²
F = P × A
F = 101325 ×0.031.
F = 3141N. Or 3.1 ×10³ N.
Answer:
The objects can be distinguished by their weight instead of by mass.
Explanation
Because mass is constant, the two objects cannot be distinguished by mass.
However, gravitational acceleration varies in outer space. Therefore the heavier mass will register a higher reading on a weighing scale.
Note that an object of mass M weighs Mg, where g = acceleration due to gravity.
Answer:
A spring is compressed and held at compression by a person before releasing it
Explanation:
All the other answers are showing things that are at rest and have no energy starting nor going through them. This answer show how the energy is starting and being released.
If two different substances, with the same mass (1 gram) absorb the same amount of energy "the temperature of the substance with the lower specific heat will increase more than the one with a higher specific heat".
Option B
<u>Explanation:</u>
The thermodynamic function that specifies the amount of heat needed by one degree of temperature for a single unit of mass of a material to be elevated is understood as "Specific heat". Depending on the extent to which they absorb heat, various levels of specific heat values are seen for the materials.
The heat transferred relies on three factors: temperature change, weight of the device, material change and stage of the material. The average temperature of the molecules increases as the material heats up, so when they collide they are more likely to contribute enough energy to cause rotation and vibration to happen as the energy moves to a higher state.
