Chemistry Chp 2
ion
A neutral atom has an equal number of protons and electrons. If there are more or less of one than the other, the atom is an ________
an ion
An atom has nine protons and ten electrons. This makes it
128.44 amu
An unknown element X has the following isotopes: 126 X (22.00% abundant), 128X (34.00% abundant). 130X (44.00% abundant). What is the average atomic mass in amu of X? Multiply mass number for each isotope of its abundance in decimal form and add them together.
molecular; nonmetal
Carbon dioxide is a __________ compound composed two types of __________ atoms
all ionic
Classify the following compounds as ionic of covalent. BaO, Fe2O3, ZnO
two nonmetals
Covalent bonds occur between two
A
Determine the correct formula for aluminum oxide A) Al2O3 B) AlO C) AlO2 D) AlO3
C
Determine the number of protons (p) and electrons (e) in Mg2+ A) 10 p, 12 e B) 12 p, 12 e C) 12 p, 10 e D) 12 p, 14 e E) 10 p, 10 e
Dalton's atomic theory
Elements are composed of atoms. Compounds are composed of atoms of more than one element. A chemical reaction involves the rearrangement of atoms. All atoms of a given element are identical Atoms are indestructible
87
How many chlorine atoms are in 29 molecules of chloroform, CHcl3?
A
How many protons and electrons are found in a Se2- ion? A) 34 p, 36 e B) 34 p, 32 e C) 32 p, 34 e D) 36 p, 34 e E) 34 p, 34 e
They have equal charges
Ignoring the sign, which has a greater magnitude of charge?
The law of multiple proportions
In two chemical reactions, 4.0 grams of oxygen combine with 3.0 grams of carbon to form one compound, and 3.0 grams of oxygen combine with 3 grams of carbon to form another. This can be explained by:
metal and nonmetal
Ionic bonds occur between a
CH
Polystyrene is made up of a series of styrene (C8H8) monomer units. What is the empirical formula for styrene?
alpha particles
Positively charged particles of radiation emitted from the decay of radioactive substances are known as
atomic mass
The ___________ is an average that represents the abundance of each isotope.
The presence of different isotopes
The atomic mass of germanium (Ge) on the periodic table is 72.630 amu. Which of the following best explains why the atomic mass is a fraction between 72 and 73?
C
The empirical formula of a covalent compound is CH2. Which of the following is NOT a possible chemical formula for this compound? a) C5H10 B) C7H14 C) C6H10 D) C4H8 E) C3H6
Ruthenium (Ru)
What element with a mass number of 100 has 56 neutrons in its nucleus?
61
What is the atomic number for an element whose mass number is 145, which contains 84 neutrons per atom? SUBTRACT
silver nitrite
What is the correct IUPAC name for AgNO2?
silver iodide
What is the correct IUPAC name for Agl?
gold(III) oxide
What is the correct IUPAC name for Au2O3?
cobalt(III) phosphate
What is the correct IUPAC name for CoPO4?
copper(II) oxide
What is the correct IUPAC name for CuO?
rubidium nitride
What is the correct IUPAC name for Rb3N?
strontium nitrate
What is the correct IUPAC name for Sr(NO3) 2?
C
What is the formula for an ionic compound containing Ba2+ ions and Cl- ions? A) BaCl B) Ba2Cl C) BaCl2 D) BaCl3 E) Ba3Cl
D
What is the formula of a compound containing Ba2+ and N3- ions? A) Ba2N3 B) Ba3N C) BaN3 D) Ba3N2
A
Which has the correct name-formula combination? A) Barium oxide - BaO B) Lithium nitride - LiN C) Aluminum sulfide - AlS D) Rubidium phosphide - RbP
E
Which is not one of Dalton's hypotheses of atomic theory? A) Elements are composed of atoms B) Compounds are composed of atoms of more than one element C) A chemical reaction involves the rearrangement of atoms D) All atoms of a given element are identical E) The atoms of one element are the same as atoms of another element
A
Which of the following compounds contains a polyatomic ion? A) NH4Cl B) CoCl2 C) H2O D) KBr
A
Which of the following compounds exhibits both ionic and covalent bonding? A) CaSO3 B) SO3 C) S3Cl2 D) CoS
B
Which of the following is best classified as a covalent compound? A) Sr3N2 B) N2O5 C) Li3N D) AlN
C
Which of the following pairs represent isotopes? A) ^28Si and ^28Si^4+ B) ^28Si and ^28Al C) ^28Si and ^29Si D) ^28Si and ^28Si^4- E) ^28Si^4+ and ^28Al^3+
C
Which of the following represents a species with 16 protons and 18 electrons? A) Ar B) S C) S2- D) Si4- E) S2+
II and III only
Which of the following statements about subatomic particles are false? I. Neutrons reside inside of the nucleus II. The atomic number is equal to the number of neutrons in the nucleus of an atom III. Electrons are more massive than protons
proton and neutron
Which particle(s) may be found in the nucleus of an atom?
Ernest Rutherford
Which scientist developed the nuclear model of the atom?
HC2H3O2
Write the chemical formula for acetic acid
AsF5
Write the chemical formula for arsenic pentafluoride
Ba(OH)2 X 8H2O
Write the chemical formula for barium hydroxide octahydrate
N2O4
Write the chemical formula for dinitrogen tetraoxide
H3PO4
Write the chemical formula for phosphoric acid
isotopes
____________ are forms of the same element that differ in the number of neutrons but contain the same number of protons. The standard notation for an _____________ is to indicate the mass number because its protons and electrons do not change.
electrons and protons
____________________ have opposite charges that are equal in magnitude
