Earth and Physical Science Flashcards
Mass
Is the quantity of matter something possesses, and usually has a unit of weight associated with it.
Matter:
commonly defined as anything that takes up space and has mass.
what two types of change can matter undergo?
Chemical and Physical
Chemical Change:
occurs when an original substance is transformed into a new substance with different properties. An example would be the burning of wood, which produces as and smoke.
Physical change
Transformation that do not produce new substances, such as stretching a rubber band or melting ice.
What are the fundamental properties which we use to measure matter?
mass, weight, volume, density, and specific gravity
Extrinsic:
properties are directly related to the amount of material being measured, such as weight and volume…
Intrinsic
properties are those which are independent of the quantity of matter present, such as density and specific gravity.
Atom
the ultimate particle of matter:
smallest particle of an element that still is a part of that element.
Center of an atom is called?
Nucleus
Nucleus is made up of what two particles?
positively-charged particle called proton
and particle that has no charge called neutron
The nucleus of an atom is surrounded by negatively-charged particles called?
Electrons.
Molecular Weight
a Mole is the amount of substance that contains 6.02 X 10(23) basic particles.
What is atomic weight?
The weight of one mole of an element.
How is the the atomic weight or mass of the atom figured?
by the total number of protons and neutrons in the atom’s nucleus.
What is an element?
a substance which cannot be broken down by chemical means, composed of atoms that have the same atomic number and are defined by the number of protons and neutrons they have. In general the elements increase in mass from left to right and from top to bottom on the periodic table.
Isotope
element having one or more form. example carbon
approximately how many elements are there?
109 known elements
88 of these occurs naturally on earth while the other are synthesized
Hydrogen
the most abundant element in the universe.
Helium
is the second most abundant element.
Earth is composed mostly of what?
iron, oxygen, silicon, and magnesium.
90% human’s body mass consists of oxygen,carbon,hydrogen, nitrogen, calcium, and phosphorus.
75% of elements are metals
11 are gasses in their natural state
molecule
smallest part of a substance that isn’t chemically bonded to another atom.
Chemical formulas
used to represent the atomic composition of a molecule.
ex. H2O
Compounds
substances that contain more than one type of element.
What are compounds that are made up of molecules which are all identical called?
pure substances.
mixture
consists of two or more substance that are not chemically bonded. mixtures are generally placed into two categories: homogeneous, heterogeneous
Homogeneous Mixture
Components that make up the mixture are uniformly distributed; ex are water and air
Heterogeneous Mixture
components of the mixture are not uniform;they sometimes have localized regions with different properties. ex. the different components of soup make it a heterogeneous mixture. Rocks as well are not uniform and have localized regions with different properties.
Solution
a uniform or homogenous mixture of different molecules
If the solution is a liquid, the material being dissolved is called what?
Solute
The liquid that a solute is being dissolved in is called what?
Solvent
Saturated
reached a point of maximum concentration, in it no more solute will dissolved
States of Matter are usually grouped into what 3 main categories
solids, liquids, gases
Solids
Rigid: they maintain their shape and have strong intermolecular forces. Typical solids are rigid at room temperature. In solids the molecules are closely packed together, and solid materials usually have a high density. In the majority of solids, called crystalline solids, the ions or molecules are packed into crystal structure that is highly ordered.
Liquids
cannot maintain their own shape, confirm to their containers, and contain forces strong enough to keep molecules from dispersing into spaces. Solids will generally become liquids when heated to a high enough temperature.
Gases
Have indefinite shape; disperse rapidly through space due to random movement and are able to occupy any volume. They are held together by weak forces. Gases are produced when liquids are heated enough, and have an additional energy associated with them called the enthalpy of vaporization. this is the energy required to break the liquid bonds, and allow the material to transfer to the gaseous phase.
What are two specific states of matter?
liquid crystals -which can maintain their shape as well as be made to flow
Plasmas-gases in which electrons are stripped from their nuclei
four properties of gases related to each other are?
- Volume of the gas
- Pressure of the gas
- Temperature of the gas
- The number of the gas molecules
3 laws that relate to gases are?
Boyle’s law- the volume of a given number of gas at a constant temperature is inversely proportional to pressure. In other words; if the initial volume decreases by half, the pressure will double and vice versa. equation is P1V1=P2V2
Charle’s law-the volume of a given amount of gas at a constant pressure is directly proportional to absolute (Kelvin) temperature. If the temperature of the gas increases, the volume of the gas also increases and vice versa. The representative equation is V1/T1=V2/T2.
Avogadro’s law- Equal volumes of all gases under identical conditions of pressure and temperature contain the same number of molecules. The molar volume of all ideal gases at 0*C and pressure of 1atm. is 22.4 liters.
Kinetic theory of gases
assumes that gas molecule are very small compared to the distance between the molecules. Gas molecules are in constant, random motion;they frequently collide with each other and with the walls of whatever container they are in.
Ideal gas law
is an important equation that is used to estimate the properties of gas at different temperatures and pressures. Called the ideal gas law because in order to be effective, the gas much be ideal, meaning:
1. the gas consists of a large number of molecule that move randomly.
2. the volume that the molecules of the gas occupies is very small compared to the to the total volume of the gas.
3. there are no attractive or repulsive interactions between the gas molecules.
Ideal gas law can be stated as: PV= nRT
P=pressure, V =volume, n=#of mols of gas, R=ideal gas constant (8.314J/molK) and T =temperature.
Periodic Table
is a chart which arranges the chemical elements in a useful, logical manner.
elements are listed in order of increasing atomic number, lined up so that elements which exhibit similar properties are arranged in the same row or column as each other.
what does each box in the periodic table contain
each box contains the symbol of the element, its atomic number, and its atomic weight.
How do elements appear on the Periodic table?
elements appear in increasing order according to their atomic numbers except for the two separate rows.
What are the vertical columns called in the periodic table
Groups: elements within a group share several common properties and often have the same outer electron arrangement. There are two categories of groups
The main group: the number of the main group corresponds to the number of the valence electrons.
The transition elements: most of these contain 2 electrons in their valence shells
What are the horizontal rows in the periodic table called?
periods: correspond to the number of occupied electron shells of the atom.
Lanthanoids
the upper row, elements set below the main table.
Actinoids
elements set below the main table in the lower row.
What are most of the elements on the periodic table?
metals, alkali metals, alkaline earth, basic metals, transition metals, lanthanides, and actinides.
Electronic Structure of Atoms:
the electrons of an atom have fixed energy levels. Those in the principle energy levels are said to be in ELECTRON SHELLS. Shells which correspond to the highest energy levels, called VALANCE SHELLS, include the electrons usually involved in chemical bonding. Chemical formulas of simple compounds can often be predicted from valences. The valence electrons increase in number as you go across the periodic table.
The electrons in the outer orbit can combine with other atoms by giving up electrons or take on electrons. Atoms that give up electrons(CATIONS)change from being neutral to having a POSITIVE charge. Atoms that gain electrons(IONS) change from being neutral to having a negative charge. The OCTET RULE is a chemical rule which states that atoms of a low atomic number will share, gain, or lose electrons in order to fill outer electron shells with eight electrons. this is achieved through different types of bonds.
Electromagnetism
is involved in all chemical behavior, including the chemical bonds which hold atoms together to form molecules, as well as those holding molecules together to form all substances.