States of Matter
Gases, liquids and solids are all made up of microscopic particles, but the behaviors of these particles differ in the three phases.
Note that:
Particles in a:
gas are well separated with no regular arrangement.
liquid are close together with no regular arrangement.
solid are tightly packed, usually in a regular pattern.
Particles in a:
gas vibrate and move freely at high speeds.
liquid vibrate, move about, and slide past each other.
solid vibrate (jiggle) but generally do not move from place to place.
Liquids and solids are often referred to as condensed phases because the particles are very close together.
The following table summarizes properties of gases, liquids, and solids and identifies the microscopic behavior responsible for each property.
Some Characteristics of Gases, Liquids and Solids and the Microscopic Explanation for the Behavior
gas liquid solid
assumes the shape and volume of its container
particles can move past one another assumes the shape of the part of the container which it occupies
particles can move/slide past one another retains a fixed volume and shape
rigid - particles locked into place
compressible
lots of free space between particles not easily compressible
little free space between particles not easily compressible
little free space between particles
flows easily
particles can move past one another flows easily
particles can move/slide past one another
The symbol : 
<h3>Further explanation
</h3>
There are two components that accompany an element, the mass number and atomic number
Atoms are composed of 3 types of basic particles (subatomic particles): <em>protons, electrons, and neutrons
</em>
The Atomic Number (Z) indicates the number of protons and electrons in an atom of an element.
Atomic number = number of protons = number of electrons ⇒ neutral number
Atomic mass is the sum of protons and neutrons
Atomic Number (Z) = Atomic mass (A) - Number of Neutrons
The element has 71 electrons and a charge of +1 , so
Number of protons = 71 + 1 = 72
Number of protons = the atomic number = 72
The element with atomic number 72 is Hafnium(Hf)
The atomic mass of Hf = 178 g/mol
Answer: C) the splitting of a nucleus released a large burst of energy
Explanation:
nuclear fission occurs when an isotope (usually unstable) is hit with particles such as neutrons and splits, resulting in an extreme burst of energy.
for instance, the atomic bombs developed by the U.S. during WWII were products of nuclear fission in which plutonium-239 and uranium-235 were struck by a neutron that hit either nucleus of either isotope. The result was the neclus split into fragments that released huge amounts of energy snd the fission process became self-sustaining as neutrons produced by the splitting nucleus hit other nuclei and produce more fission, causing a chain reaction.
