Chem chapter 2
number of protons
All atoms of a given element have the same __________.
a metal
An element that appears in the lower left corner of the periodic table is _________
the simplest whole-number ratio of different atoms in a compound
An empirical formula always indicates __________.
electrons
Cathode rays are __________.
2
Di-
neutrons
Different isotopes of a particular element contain different numbers of __________.
Atomic Theory of Matter- John Dalton
Each element is composed of extremely small particles called atoms. All atoms of a given element are identical to one another in mass and other properties, but the atoms of one element are different from the atoms of other elements. Atoms of an element are not changed into atoms of a different element by chemical reactions; atoms are neither created nor destroyed in chemical reactions. Compounds are formed when atoms of more than one element combine; a given compound always has the same relative number and kind of atoms.
Alkali metals
Elements in Group 1A are known as the __________.
alkaline earth metals
Elements in Group 2A are known as the __________.
Chalcogens
Elements in Group 3A are known as the __________.
halogens
Elements in Group 7A are known as the __________.
Noble gasses
Elements in Group 8A are known as the __________.
1-
Fluorine forms an ion with a charge of __________.
Diatomic Molecules
Hydrogen H₂ Nitrogen N₂ Oxygen O₂ Fluorine F₂ Chlorine Cl₂ Bromine Br₂ Iodine I₂
+1
In subatomic particles Protons have what charge?
the heavy subatomic particles, protons and neutrons, reside in the nucleus
In the Rutherford nuclear-atom model, __________.
order of increasing atomic number
In the periodic table, the elements are arranged in ________
The mass number
In the symbol below, x is __________. xC 6
1
Mono-
α-rays and β-rays
Of the three types of radioactivity characterized by Rutherford, which is/are electrically charged?
3, 4
On the basis of Rutherford's experimental observations, which of the following statements describes the structure of the atom according to Rutherford's atomic model? 1. In an atom, all of the positive and negative charges are randomly distributed. 2. In an atom, positively charged particles are dispersed in the space surrounding the negatively charged sphere. 3. In an atom, the positive charges are located in a small core within the atom called the nucleus. 4. In an atom, negatively charged electrons are dispersed in the space surrounding the positively charged nucleus of an atom.
5
Penta
4
Tetra-
the number of protons or electrons in a neutral atom
The atomic number indicates __________.
+2
The charge on the copper ion in the salt CuO is _________
aluminum oxide
The correct name for Al2O3 is __________
hydrogen nitrate
The correct name for HNO2 is __________.
nitric acid
The correct name for HNO3 is __________.
sodium bicarbonate
The correct name for NaHCO3 is __________.
electrons
The nucleus of an atom does not contain __________.
Law of conservation of mass
The total present at the end of a chemical process is the same as the mass of substances before the process took place. Atoms of an element are not changed into atoms of a different element by chemical reactions; atoms are neither created nor destroyed in chemical reactions
3
Tri-
1, 3, 4, 6
Watch the animation depicting Rutherford's experiment and choose which of the following conclusions are correct. Check all that apply. 1. The mass of an atom is concentrated at the nucleus. 2. A positive charge is spread equally over the atom. 3. Positive charge is condensed in one location within the atom. 4. The majority of the space inside the atom is empty space. 5. The atom is a very compact entity without any empty space. 6. The atom contains a positively charged nucleus.
metal, nonmetal
When a metal and a nonmetal react, the __________ tends to lose electrons and the __________ tends to gain electrons.
atomic number
all atoms have the same number of protons. written as a subscript before the symbol
Gold Foil Experiment Ernest Rutherford
alpha particles at a thin gold sheet of foil and observed the pattern of scatter of the particles
Plume Pudding Model
atom consists of a uniform positive sphere of matter in which the mass is evenly distributed and in which the electrons are embedded like raisins
isotopes
atoms on the same element with different masses different number of neutrons, but same number of protons.
groups
columns on the periodic table
molecular compound
composed of molecules and almost always contain non metal
metalloids
elements on the steplike line of the periodic table properties are sometimes like metals and sometimes non metals
Ionic compounds
formed between metals and non metals electrons are transferred from the metal to the nonmetal. The opposite charged ions attract each other.
Anions
formed when at least one electron is gained
Average mass
found using all isotopes of an element weighted by their relative abundances.
Molecular formulas
give the exact number of atoms of each element in a compound
Empirical Formula
give the lowest whole number ratio of atoms of each element in a compound
-1
in subatomic particles Electrons have what charge?
metals
left side of the periodic table 1. shiny luster 2. conduction heat 3. solidity
non metals
right side of the periodic table (with the exception oh H) can be solid, liquid, or gas at room temperature
periods
rows on the periodic table
Chemical formulas
the subscript to the right of the symbol of an element tells the number of atoms of that element in one molecule of the compound
mass number
total number of protons and neutrons in the nucleus of an atom.
structural
type of formula provides the most information about a compound?
Ions
when an atom of a group go atoms loses ir gains electrons
Cations
when one electron is lost.
