Download CHEM 101 Dual Enrollment HW4 Question 1 of 12 Dalton`s

CHEM 101 Dual Enrollment
HW4
Question 1 of 12
Dalton's postulates, also known as Dalton's atomic theory, include some proposals that have been
updated or changed due to new discoveries. Which of the following statements were parts of Dalton's
original atomic theory? Select all that apply.
Atoms of the same element have the same size, mass, and structure.
Different elements have atoms of different masses and properties.
Matter is comprised of small particles called atoms.
Atoms cannot be created or destroyed in a chemical reaction.
Question 2 of 12
Atomic theory, as we know it today, is the result of the contributions of many scientists who did the
research, disproved old models and suggested the new ones, and added to the atomic theory. The items
below are the concepts that were developed in the history of the atomic theory. Rank them in order from
oldest to most recent.
electrons are in orbits
plum pudding model
positively-charged atomic nucleus
atoms of the same element have the same properties
Question 3 of 12
In 1911, Hans Geiger and Ernest Marsden (working under Ernest Rutherford) conducted an experiment
involving alpha particles and gold foil that led to the discovery of the nucleus in atoms.
The nucleus of an atom accounts for ...
most of the size and mass of the atom.
very little of the size and mass of the atom.
most of the atom's size but very little of its mass.
most of the atom's mass but very little of its size.
Question 4 of 12
Write the element name that corresponds to the following element symbols. Spelling counts!
Mg
Ni
Si
Question 5 of 12
Classify each of the following elements as
Sb As Ga Sn Xe Bi Kr
Metals
Semimetals (metalloids)
Question 6 of 12
Which of the following statements accurately describe all halogen elements? Mark all that apply.
They react with alkali metals to form salts.
They are highly reactive.
They have the same boiling point.
They have one electron missing in their outer shell.
They only have one electron in their outer shell.
Nonmetals
Question 7 of 12
Label these groups of the
periodic table.
halogens
alkali metals
alkaline earth metals
noble gases
Question 8 of 12
Complete this table for neutral isotopes.
Element:
Se
Mass number:
79
65
Number of neutrons:
36
Number of protons:
Number of electrons:
47
36
Question 9 of 12
Give the nuclear symbol (isotope symbol) for the isotope of bromine, Br, that contains 46 neutrons per atom.
Question 10 of 12
The element carbon (C) has two common isotopes. 98.89% of carbon atoms have 6 neutrons and 6
protons, whereas the other 1.11 % has 7 neutrons and 6 protons. Using the isotopic composition provided,
calculate the average atomic mass of carbon (in amu). Round your answer to the tenths place.
Question 11 of 12
How many protons are in an ion with 10 electrons and a -1 charge?
2+
How many total electrons are in a Sr ion?
Question 12 of 12
Select all the true statements.
IAnions carry a positive charge.
2+
3+
The Fe and Fe ions have the same number of protons.
+
The K ion is formed when a potassium atom loses one electron.
+
2+
The Cu and Cu ions have the same number of electrons.
The CI and Br ions have the same number of electrons.
When an atom gains an electron, it becomes a cation
?
? Br