Chapter 1: Atoms and Elements Flashcards
What causes compounds with the same number of an element to have different properties? (i.e. beef fat and olive oil having the same number of carbon atoms)
the difference in structure
What are the steps of the scientific method?
observation, hypothesis, experiments, revision, and developing a theory
What are all elements composed of?
Atoms
What are the three parts of Dahlton’s Postulate?
- Each element is composed of atoms
- all atoms of the same element have the same properties and these properties differ between elements
- Elements combine in simple, whole number ratios to form compounds
What model did Thompson develop?
The plum pudding model
What model did Rutherford develop?
The gold foil model
Where is most of the mass of an atom located?
The nucleus (center)
What is most of an atom’s volume composed of?
empty space containing the electrons
What is the electric charge of an atom?
neutral
What is the abbreviation for a proton?
p+
What is the relative charge of a proton?
+1
What is the mass of a proton?
1.67X10^-27
Where are protons located?
in the nucleus
What is the abbreviation for a neutron?
n0
What is the relative charge of a neutron?
0
What is the mass of a neutron?
1.67X10^-27
Where are neutrons located?
in the nucleus
What is the abbreviation for an electron?
e-
What is the relative charge of an electron?
-1
What is the mass of an electron?
-1
Where are electrons located?
outside of the nucleus
What is Z?
atomic number and number of protons
what is A?
mass number (protons+neutrons)
What is X?
the atomic symbol (letter(s))
How do you calculate the mass number?
protons+neutrons
What is group 1?
alkali metals
What is group 2?
alkaline earth metals
What is group 7?
halogens
What are halogens called when they form ionic compounds?
halides
What is group 8?
noble gases
What are the three categories of elements called?
metals, non-metals, and metalloids
What are the three regions of the period table called?
main-group, transition metals, and the lanthanide actinide series
All atoms of the same element have the same number of what?
protons
Not all atoms of the same element have the same number of what?
neutrons
What is an isotope?
atoms with the same number of protons but different numbers of neutrons
What is atomic mass not equal to?
the mass number (A)
What is the atomic mass?
the weighted average of all naturally occurring isotopes of an element
What does AMU stand for?
atomic mass units
How do you calculate the atomic mass?
%abundance of isotope 1 (mass of isotope 1) + %abundance of isotope 2 (mass of isotope 2) …..
How many sig. digits are in 1.2430?
5
How many sig. digits are in 0.0002?
1
Which has more force: objects 2 cm apart or objects 4 cm apart?
objects 2 cm apart
Which has more force: objects with charges of 2 and 1 or objects with charges of 1 and 1?
objects with charges of 2 and 1
What is matter?
anything that has mass and takes up space
Opposite charges are _____ to each other
attracted
Like charges _____ each other
repell
The larger the charge, the ____ the interaction
stronger
The closer together, the ____ the intereaction
stronger
Opposite charges ____ each other out
cancel
What is contained in the nucleus of an atom?
neutrons and protons
The nucleus accounts for almost all of the ____ of an atom
mass
The nucleus only accounts for a tiny amount of the ____ of an atom
volume
When the number of protons is equal to the number of electrons, the charge of the atom is ____
neutral
What are the letters used to identify an element called?
the chemical symbol
What are the vertical columns of the periodic table called?
groups
What are the horizontal rows of the periodic table called?
periods
Elements in the same group have the same _____
properties
The mass number is equal to _____+______
protons, neutrons
What are nucleons?
protons and neutrons collectively together
What is the equation for atomic mass?
A=m1p1+m2p2…..
Which of the following shows cancelled charges? A. 10+ 10- B. 20+ 21- C. 15+ 18- D. 16+ 13-
A
A neutral atom contains the same number of protons and _____
electrons
The number of _____ does not affect the charge of an atom
neutrons
In a ____ atom, the number of electrons always equals the number of protons
neutral
A ____ is the smallest identifiable piece of an element and has the same properties as the element
atom
Which isotope has the higher abundance:
A. NI-58 or Ni-60
B. K-39 or K-41
C. Fe-54 or Fe-56
A. Ni-58
B. K-39
C. Fe-56
