Chemistry 101, Chapter 1: Atoms

Avogadro's number?

1 mol = 6.022 X 10²³ particles

The value of the mole is equal to the number of atoms in exactly ____ g of pure carbon-12

12

The difference between a law and a theory is ____________.

A law that summarizes a series of related observations, whereas a theory gives the underlying reasons for them

What is the difference between the law of definite proportions and the law of multiple proportions?

The law of definite proportions applies to two or more samples of the same compound while the law of multiple proportions applies to two different compounds containing the same two elements (A and B) Full definition: The law of definite proportions applies to two or more samples of the same compound and states that the ratio of one element to the other is always the same. The law of multiple proportions applies to two different compounds containing the same two elements( A and B) and states that the masses of B that combine with 1 g of A are always related to each other as a small whole-number ratio.

A negatively charged ion is called an ________.

anion

Characterized as ____________, This is the average mass in amu of the atoms of a particular element based on the relative abundance of the various isotopes; numerically equivalent to the mass in grams of one mole of the element.

atomic mass (atomic weight)

A ___________ is a unit used to express the masses of atoms and subatomic particles; defined as 1/12 the mass of a carbon atom containing 6 protons and 6 neutrons.

atomic mass unit (amu)

The number of protons in an atom is called the _________ symbolized by Z; the atomic number defines the element.

atomic number (Z)

This theory say that each elements is composed of tiny indestructible particles called atoms, that all atoms of a given element have the same mass and other properties, and that atoms combine in simple, whole-number ratios to form compounds.

atomic theory

________ are the basic particles that compose ordinary matter, and about 91 different types of these naturally exist.

atoms

A __________ is a stream of electrons produced when a high electrical voltage is applied between two electrodes within a partially evacuated tube.

cathode ray

A ________ is a partially evacuated tube equipped with electrodes to produce cathode rays.

cathode ray tube

A positively charged ion is called a ________.

cation

A ___________________ is a process in which one or more substances are converted into one or more different substances. The law of conservation of mass states that when a chemical reaction occurs, the total mass of the substances involved in the reaction does not change.

chemical reaction (matter is neither created nor destroyed)

A one- or two-letter abbreviation for an element that is listed directly below its atomic number on the periodic table is the ________________.

chemical symbol

This field of science seeks to understand the properties of matter by studying the structure of the particles that compose it.

chemistry

The _________ of matter depends on the types of particles.

composition

The types of particles that compose matter is called its __________.

composition

Water is a pure substance; therefore it is a good example of a/an _________, a substance composed of two or more elements (in this case hydrogen and oxygen) in fixed, definite proportions.

compound

The large spaces between gas particles makes them __________.

compressible

A __________ is the fundamental property of certain particles that causes them to experience a force in the presence of electric fields.

electrical charge

A __________ is a negatively charged, low-mass particle found outside the nucleus of all atoms that occupies most of the atom's volume but contributes almost none of its mass

electron

Helium is a pure substance; therefore, it is also a good example of a/an _________, a substance that cannot be chemically broken down into simpler substances.

element

A pure substance can be either an __________ or a __________, depending on whether or not it can be broken down (or decomposed) into simpler substances.

element, compound

The particles that compose __________ matter attract each other only weakly - so weakly that they do not clump together as particles do in a liquid or solid. Instead the particles are free to move large distances before colliding with one another. Ex: helium, nitrogen, and carbon dioxide

gaseous

Water and sand is a ___________ ___________, one in which the composition varies from one region of the mixture to another - the different particles that compose water and sand do not mix uniformly.

heterogeneous mixture

A mixture can be either _______________ or _______________, depending on how uniformly the particles that compose the mixture combine.

heterogeneous, homogeneous

Sweetened tea is a ____________ ___________, one with the same composition throughout - the particles that compose sweetened tea mix uniformly.

homogeneous mixture

An _________ is an atom or molecule with a new charge caused by the loss or gain of electrons.

ion

An _____________ is one of two or more atoms of the same element with the same number of protons but different numbers of neutrons and consequently different masses.

isotopes

This law states that all samples of a given compound, regardless of their source or how they were prepared, have the same proportions of their constituent elements. (sometimes called the law of constant composition)

law of definite proportions

This laws states that when two elements (call them A and B) form two different compounds, the masses of element B that combine with 1 g of element A can be expressed as a ratio of small whole numbers.

law of multiple proportions

The particles that compose __________ matter pack about as closely as particles do in solid matter, but slightly weaker attractions between the particles allow them to move relative to each other, giving it a fixed volume but not a fixed shape. ex: Water, alcohol, and gasoline

liquid

The sum o the number of protons and neutrons in an atom is called the _________?

mass number (A)

An experimental method of determining the precise mass relative abundance of isotopes in a given sample using an instrument called a mass spectrometer.

mass spectrometry

Anything that occupies space and has mass is known as this?

matter

A _________, by contrast, is a substance composed of two or more particles in proportions that can vary from one sample to another. For example, sweetened tea, composed primarily of water molecules and sugar molecules (with a few other substances combined).

mixture

The mass in grams of one mole of atoms of an element; numerically equivalent to the atomic mass of the element in amu.

molar mass

Atoms often bind together in specific geometrical arrangements to form _________ molecules, as in water.

molecules

The relative percentage of a particular isotope in a naturally occurring sample with respect to other isotopes of the same element.

natural abundance

A _________ is an electrically neutral subatomic particle found in the nucleus of an atom, with a mass almost equal to that of a proton.

neutron

A __________ is an electrically neutral subatomic particle found in the nucleus of an atom, with a mass almost equal to that of a proton.

neutron

_________ theory is the theory that most of the atom's mass an all of its positive charge are contained in a small, dense nucleus.

nuclear

This theory states that most of the atom's mass and all of its positive charge are contained in a small, dense nucleus.

nuclear theory

The table that arranges all known elements in order of increasing atomic number is called _________. These are elements with similar properties generally fall into columns.

periodic table

A _________ is made up of only one type of particle (one component), and its composition in invariant (it does not vary from one sample to another). The particles that compose it can be individual atoms, or groups of atoms joined together. Ex: Helium, water, and table salt (sodium chloride)

pure substance

_____________ is the emission of small energetic particles from the core of certain unstable atoms.

radioactivity

______________ is the emission of subatomic particles or high-energy electromagnetic radiation by the unstable nuclei of certain atoms.

radioactivity

The particles that compose _________ matter attract one another strongly and therefore pack closely to each other in fixed locations. Although the particles vibrate, they do not move around or past each other. It has a fixed volume and rigid shape. ex: Ice, aluminum, and diamond

solid

Matter can exist in three different states: (answer: what are these three states?)

solid, liquid, and gas

The _________ of matter depends on the relative positions of the particles and how strongly they interact with one another (relative to temperature).

state

A specific instance of matter - such as air, water, or sand - is a __________.

substance