Chemistry Ch.2 test
have a relative charge of -1 have a much lower mass than the other two types of particles
electrons
For ionic compounds, where one ion is a polyatomic ion?
(-ate, -ite, hypo- per-)
For ionic compounds?
(-ide)
What is a compound?
2 or more elements chemically combined Ex: Water, Hydrogen, Salt
Give the nuclear symbol for the isotope of bromine, Br, that contains 46 neutrons per atom
81 Br 35 Find Br, look at atomic mass, that equals the number of protons -35 then you add the number of protons and neutrons to get the mass number -81
What is a molecule?
A group of atoms bonded together Ex: H2O, N2 (nitrogen), NaCl (table salt)
What is an anion?
A negatively charged ion Ex: H- Hydride ion O2- oxide ion N3- nitride ion
Which chemical reactions are not possible according to Dalton's atomic theory?
CCl4-->CH4 2H2 + O2-->2H2O + Au
examples of molecular compounds
CO2 NCl3
Ca2+
Calcium ion
Can you classify a compound as being a covalent compound
Covalent, or molecular, compounds generally result from two nonmetals reacting with each other. The elements form a compound by sharing electrons, resulting in an electrically neutral molecule. Ex: Water, Sucrose, and DNA
Determine which ions are present in each of the compounds Cr2O3
Cr3+ O2-
F-
Fluoride ion
On the periodic table, can you identify the non-metals?
H, He, C, N, O F, Og, Exc.
On the periodic table, can you identify the noble gases?
He, Ne, Ar, Kr, Xe, Rn
What is an ion?
If electrons are removed from or added to an atom, a charged particle called an ion is formed
K+ and PO4 3-
K3PO4
On the periodic table, can you identify the alkali metals?
Li, Na, K, Rb, Cs, Fr
Given the number of protons, neutrons and/or electrons, can you write the complete atomic symbol for a neutral atom? Given a complete atomic symbol, can you determine the number of protons, neutrons and electrons in a neutral atom?
Mass Number A (Protons + neutrons) Atomic Number Z (Protons)
Examples of ionic compounds
Na2O ZnCl2
Which pair would have similar properties? S and O Ce and U Sb and Te F and Ne
S and O
N+
Sodium ion
On the periodic table, can you identify the periods?
The horizontal rows of the periodic table are called periods
On the periodic table, can you identify the rows?
The vertical columns
Elements found in between the metals and nonmetals not her periodic table display which properties ?
They are usually semiconductors They are usually less brittle than nonmetallic solids They are solids at room temperature
In the periodic table, how are elements grouped?
according to chemical and physical properties
Which of the elements are metalloids, also known as semimetals?
antimony arsenic
What is an isotope?
atoms with the same number of protons but different number of neutrons
The nucleus of an atom accounts for
most of the atoms mass but very little of its size
have no charge located in the nucleus of an atom
neutrons
What information cannot be identified if the number of protons for a neutral atom is known?
number of neutrons
have a relative charge of +1 located in the nucleus of an atom
protons
What are the subatomic particles that compose an atom?
protons, neutrons, and electrons
The mass number is equal to
sum of the number of protons and neutrons
atomic number
the number of protons in the nucleus of an atom
Elements found to the left of the metalloids on the periodic table display which properties?
they tend to form cations they tend to be malleable they tend to be good conductors
How is the atomic mass of isotopes measured
weighted average
What is a formula unit?
the simplest collection of atoms from which an ionic compound's formula can be established Ex: NaCl is the formula unit for the ionic compound sodium chloride.
For covalent compounds?
(using prefixes like mono- di- tri- tetra- penta, etc.)
For ionic compounds, when the metal has more than one possible charge?
(using roman numerals in parenthesis)
If you burn 23.0g of hydrogen and produce 205 g of water, how much oxygen reacted?
205-23=182g
What is a cation?
A positively charged ion Ex: Na+ sodium ion Zn2+ zinc ion Al3+ aluminum ion
Al3+ and CO 3 2-
Al2(CO3)3
What is an atom?
An atom is the smallest unit of matter that still remains the properties of an element.
On the periodic table, can you identify the metalloids?
B, Si, Ge, As, Sb, Te
Ba2+ and NO3-
Ba(NO3)2
On the periodic table, can you identify the alkaline earth metals?
Be, Mg, Ca, Sr, Ba, Ra
On the periodic table, can you identify the halogens?
F, Cl, Br, I, At
Can you classify a compound as being an ionic compound
Two-element compounds are usually ionic when one element is a metal and the other is a non-metal. Ex: sodium chloride: NaCl, with Na+ and Cl- ions lithium nitride: Li3N, with Li+ and N3- ions
