Answer:
meteor
Explanation:
The most logical identification of a "shooting star" is a meteor. A meteor is basically any material from outerspace that falls to Earth. The main characteristic of a meteor is that from our point of view on the surface of the Earth it looks like a shooting star because we see a streak of light behind it. This light is simply dust and rock from the meteor burning up as it enters the Earth's atmosphere, leaving a "tail" of light behind it. Which to us looks like a shooting star.
Answer:
d. at 25.0 and 1 atm
Explanation:
The standard heat of formation of a substance is the amount of heat absorbed or evolved when 1 mole of the substance is formed from from its constituent elements. It is also known as standard enthalpy of formation.
All elements in their natural states, have a standard heat of formation of zero because there is no temperature change involved in their formation. Example includes oxygen gas, graphite (solid carbon).
a. ΔH° of at standard pressure of 1 atm is zero, but not at 2 atm
b. ΔH° of Fe at 25.0 is zero, but not at 1200
c. ΔH° of is not zero because it's a compound
d. ΔH° of is zero at standard conditions
Answer:
When dealing with the force of gravity between two objects, there are only two things that are important –<u> mass, and distance</u>. The force of gravity depends directly upon the masses of the two objects, and inversely on the square of the distance between them.
Explanation:
Answer:
A). half, higher
Explanation:
The Formal charge is elaborated as the 'allocated charge to a molecules' atom' on the basis of the assumption that the electrons present in the chemical bond are equally split among the atoms. It is estimated by 'halving the no. of bonding electrons that encircle the atom.
While Oxidation number is characterized as the 'hypothetical charge of an atom that is present within a molecule.' It is also defined as 'the actual number of lost or gained electrons or the rate at which the electrons are gained or lost by an atom to develop a chemical bond along with the other atom.' It is <u>calculated by allocating or sharing the electrons having the higher electronegativity belonging to a specific bond with the other</u>. Thus, <u>option A</u> is the correct answer.
Think about it this way: a cell can only take in materials through the cell membrane. Naturally, as the cell membrane surface area increases, then the amount of material that can enter the cell increases due to more entry points along the membrane. However, when the cell increases in size then the volume inside the cell will also increase - more volume inside requires more energy to transport materials around the cell. So, there is a trade-off between the surface area and volume.
<span>As an example, consider a sphere as a cellular model. The surface area of a sphere is </span>
<span>SA = 4*pi*r^2 </span>
<span>while the volume of the sphere is </span>
<span>V = 4/3*pi*r^3 </span>
<span>initially, as a very small cell increases in radius, the surface area will increase at a greater rate than the volume. But as the cell gets bigger there will be a point where the volume increases faster than the surface area. Cells have maximized this ratio through evolution (this is also one reason why we are not single-celled organisms). </span>
<span>Some cells are able to get around this issue to some extent by "folding" the membrane, thus increasing the surface area without affecting the volume by much. </span>