<h2>
Answer</h2>
The physical state of the elements depends upon the <u>attraction forces </u>and their <u>kinetic energy</u>.
<h2>
Explanation</h2>
The elements or substances are fixed with each other with the help of different chemical forces including ionic bonding, covalent bonding, H- bonding etc. The strength of these forces is also one of the factors that affect their physical natures. For example, covalent or ionic bonds are the strongest bonds than all other bonds and metals that contain these forces are mostly in solid form. The kinetic motion of electrons in the element also affects the physical state of the element and potential of bonding.
Answer:
Oxidation
Explanation:
The browning of the apple after you cut it undergoes a natural chemical change called oxidation, wherein the apple's enzymes react with the oxygen in the environment.
Given: Heat Qout means useful work = 2800 J
Heat Qin = 8900 J
Required; Efficiency = ?
Formula: Efficiency = Qout/Qin = x 100%
= 2800 J/8900 J = 0.3146 X 100 %
Efficiency = 31.46%
Answer:
Number of electrons, 
Explanation:
It is given that,
Resistance, R = 4 ohms
Current, I = 3 A
Time, t = 5 min = 300 s
We need to find the number of electrons pass through the resistor during this time interval. Let the number of electron is n.
i.e. q = n e ...............(1)
And current, 
e is the charge of an electron
So, the number of electrons pass through the resistor is 
. Hence, this is the required solution.
The tow lines for the two skiers must be of the same length. No matter the number of skiers towed, the length of the tow lines must be the same. Towing people on ski requires additional skills and some safety precautions must be taken. Most importantly, it is dangerous and illegal to tow at night.
