Module 2 Flashcards
Do electrons repel each other?
yes!
What makes most of an atom’s mass?
protons and neutrons
Are protons attracted to a neutron?
no
What compromises almost 100% of an atom’s volume?
The electron cloud
What determines the identity of an atom ?
The number of protons in the nucleus
if an element has 12 neutrons, can we figure out what it is?
no bc its based on protons
if calcium has a mass number of 42 how many neutrons?
22
40 - 20 = 22 (subtract the protons from mass # to get neutrons - remember it is a neutral and stable atom)
Sodium (Na) has a mass number of 23. How many protons, neutrons and electrons does this neutral sodium atom have?
11, 12, 11
Silver (Ag) has a mass number of 107. How many protons, neutrons and electrons does this neutral silver atom have?
47, 60, 47
An neutral atom has 33 electrons. Which element is it?
arsenic
How many neutrons are in an iron (Fe) atom that has a mass number of 56?
30
What are the number of protons, neutrons and electrons in the following isotope?
89 38Sr
38 protons, 51 neutrons, 38 electrons,
What are the number of protons, neutrons and electrons in the following isotope?
5224Cr
24, 28, 24
what is an isotope?
An isotope is a variant of a particular chemical element that has the same number of protons in its nucleus but a different number of neutrons. This means that isotopes of an element have the same atomic number (which defines the element) but different mass numbers.
What is the atomic symbol for the isotope that has 15 protons and 16 neutrons?
31 15 P
What is the atomic symbol for the isotope that has 35 protons and 45 neutrons?
80 35 Br
What is the atomic symbol for a mercury atom with 122 neutrons?
202 80 Hg
Two isotopes of gallium are naturally occurring with 6931Ga at 60.11% (68.93 amu) and 7131Ga at 39.89% (70.92 amu). Calculate the atomic mass for gallium using the weighted average mass method.
69.72
Two isotopes of rubidium occur naturally with 8537Rb at 72.17% (84.91 amu) and 8737Rb at 27.83% (86.91 amu). Calculate the atomic mass for rubidium using the weighted average mass method.
85.47 amu
What are alkali metals?
group 1a
very reactive, malleable, ductile
can explode when expose to water
one loose electron
What are alkaline earth metals?
group 2
low electron affinity and electronegativity
two electrons in the outer shell
smaller atomic radius than alkali metals
readily form divalent cations
Transitions metals, what are they ?
group 3 - 12
fairly unreactive, malleable
high melting and boiling points
low ionization energies
What are halogens?
has very high electronegativities
seven valence electrons
highly reactive with alkali and alkaline earth metals
low ionization energies
what are mettaloids ?
properties of non metals and metals
silvery mettalic
semi conductors
solid at room temperature
Give the symbol of the element described by the following:
group 14, period 3
si
Give the symbol of the element described by the following:
an alkali metal in period 3
na
Which atom in the pair is larger? Na or Cl
Na
Which atom in the pair is larger? Na or Rb
Rb
Place the elements in order of decreasing atomic size:
Cl, I, Br
I, Br, Cl
Which group on the periodic table are colourful and reactive non-metals?
group 7
Which group on the periodic table are highly reactive, silvery, soft metals?
group 1
Which group on the periodic table are chemically inert, colourless gases?
group 8
What is the maximum electrons that can occupy the 4th shell?
32
What is the maximum electrons that can occupy the 3d subshell?
10
What is the maximum electrons that can occupy the 4f subshell?
14
What is the maximum electrons that can occupy the 2p subshell?
6
’
