Alkali metals: left column of your periodic table (not hydrogen, but anything below it). They have one valence electron, which they are happy to share in a reaction.
Halogens: second column from the right of your periodic table. They are one electron short of a full shell, so they are reactive in the opposite way that alkalis are--they want electrons.
Atomic number (number of protons) is the big number on the periodic table square. Hydrogen's is 1.
Atomic mass is a little number down below. For example, Hydrogen's is 1.008.
Neutrons are a tricky subject, because different isotopes of the same element can have different numbers of neutrons. You can't generally get this from the atomic mass, because the atomic mass is a weighted average of naturally occurring isotopes. Hydrogen can have 0,1, or 2 neutrons. To answer this, you'd have to choose a particular isotope from the table of isotopes (a completely different chart from the periodic table) which has a certain number of neutrons: n = weight - Z.
Valence electrons are the electrons in the outermost shell. (The column of the table).
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Number of principal shells is the row of the periodic table. </span>
So to get the volume, you're going to multiply all three together, but you have to make all the units the same first. The answer wants ft³, so you want to convert them all to feet.
height = 109 ft, so that's fine already. Awesome.
width = 710 yd, but that's an easy conversion to feet. Three feet equal one yard, so just multiply (710 yd) by (3 ft/1 yd) and that'll give you the width in ft.
length = 634 m
This one is a little tricker, but same principle. First convert meters to centimeters, like this: (634 m)(100 cm/1 m). Then take that number in cm and convert it into inches, knowing that 1 inch = 2.54 centimeters. So multiply the inches you have by (1 in/2.54 cm). Then you'll change that number into feet by dividing it by twelve, since there are twelve inches in each foot.
Now you have all three measurements in feet. Just multiply them together to get the volume in ft³ and you're good to go! :)
Complete Question:
Metal sphere A has a charge of − Q . −Q. An identical metal sphere B has a charge of + 2 Q . +2Q. The magnitude of the electric force on sphere B due to sphere A is F . F. The magnitude of the electric force on sphere A due to sphere B must be:
A. 2F
B. F/4
C. F/2
D. F
E. 4F
Answer:
D.
Explanation:
If both spheres can be treated as point charges, they must obey the Coulomb's law, that can be written as follows (in magnitude):
As it can be seen, this force is proportional to the product of the charges, so it must be the same for both charges.
As this force obeys also the Newton's 3rd Law, we conclude that the magnitude of the electric force on sphere A due to sphere B, must be equal to the the magnitude of the force on the sphere B due to the sphere A, i.e., just F.
Answer:
b. electric potential energy.
Explanation:
The energy required to move a charge against the electric field is known as the electric potential energy. As in above case positively charged body is exerting an electric field on the positive charge. As the same charges repel so the charge tend to move away. In order to push it towards the body we need a work done. As it is hard to push the positive charged particle towards the positive electric field. So in the cases like these particle occupies the electric potential energy.
Answer:
Water
Explanation:
Because it does not conduct much energy.
