Answer:
An atom is made of protons and neutrons which make up the nucleus and electrons that are around the nucleus. Although almost all the mass of an atom is in the nucleus, most of the space that the atom takes up is occupied by the electrons.
In very simple terms, the electrons are in orbits around the nucleus so most of the volume of the atom is empty space within the volume that the electrons occupy. The behaviour of the electrons is often assumed to be orbits but their actual positions are not that simple.
As a final note, all atoms contain neutrons with the exception of hydrogen which can exist as one proton and one electron.
Explanation:
Answer:

Explanation:
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In this case, since Helium is undergoing a volume-pressure change, according the Boyle's law, we infer the following equation is used:

Thus, since we are not given the volume at 0.25 atm, we can solve for V2 to do so:

Thus, we plug in to obtain:

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Answer:
increases the frequency of particle collisions
Explanation:
One factor upon which the rate of reaction depends is the surface area of reactants.
According to the collision theory, reactions occur when reactant particles having the required (activation) energy collide with each other, this collision is inelastic. However, collision of particles having energies less than the activation energy results in elastic collisions and no chemical reaction.
The more the exposed surface area of reactants, the greater the number of particles that come into contact with each other and the more the chances of frequent effective collisions that lead to reaction.
Thus, powdered zinc reacts faster with hydrochloric acid than zinc strips
It has 4 valence electron, all of which are needed to bond with nearest neighbors
Answer:
Explanation:
Carbon group element, any of the six chemical elements that make up Group 14 (IVa) of the periodic table—namely, carbon (C), silicon (Si), germanium (Ge), tin (Sn), lead (Pb), and flerovium (Fl).
Elements: Lead; Germanium; Silicon; Tin; Carbon,silicon,germanium,tin,lead,and flerovium