Atomic Structure Flashcards
How many outer electrons does magnesium have?
Which group is magnesium found in?
How many electron shells does magnesium have?
What period is it found in?
2 outer electrons
Group 2 - called the Earth Alkaline metals
3 electron shells
Period 3
What does the group number in the periodic table represents?
The number of outer electrons
What is the electronic configuration of helium-4 with a proton number of 2.
2 in the first shell
4 is the mass number, since it is neutral it will have 2 electrons to equal the number of protons (+2) + (-2) = 0
Why is group 0 or the noble gases inert (unreactive)?
They have a full outer shell
Name the subatomic particles which are also nucleons.
proton and neutrons because they are found in the nucleus
To which group and period does this element belong?
Chlorine-35
Chlorine has a proton number of 17
The proton number is 17 therefore it has 17 electrons.
The electronic configuration is
2,8,7
group 7 - it has 7 outer electrons
period 3 - it has 3 electron shells
Which two ions have an electronic configuration of 2,8,8?
Cl 1- and K 1+
Chlorine is 2,8,7 and gains one electron to become 2,8,8 and gains a charge of 1-
Potassium is 2,8,8,1 and losed one electron to become 2,8,8 and gains a charge of 1+
What subatomic particles are found in the nucleus?
protons and neutrons
Naturally occurring chlorine consists of atoms of relative masses 35 (75%) and 37 (25%). Without calculating which RAM is more likely and why? 37.5, 35.5. or 36.0
35.5 because the number is closest to 35 which has a greater abundance of 75%.
Define relative atomic mass (RAM)
The average mass number of an atom relative to 1/12th the mass of Carbon-12 taking into consideration the abundance of all its isotopes.
Which element has 8 outer electrons?
Ne-10 proton number 8
OR O-16 proton number 8
Neon - its electronic configuration is 2,8
Neon has 10 electrons but 8 outer electrons
What is the charge of a proton, neutron and electron respectively?
proton 1+, neutron 0, electron 1-
How do you find the number of neutrons found in Na-23 which has a proton number of 11.
mass number - proton number = number of neutrons 23 - 11 = 12 neutrons
What is the electronic configuration of N3-
Nirogen has a proton number of 7.
2,8
Nitrogen is 2,5 but it has gained 3 electrons to give N 3-
What does the period number represent in the periodic table?
The number of electron shells
How many outer electrons does aluminium have?
Which group is aluminium found in?
How many electron shells does aluminium have?
What period is it found in?
3 outer electrons
Group 3
3 electron shells
Period 3
What is the electronic configuration of oxygen-16 with a proton number of 8?
2,6
Check:
oxygen is in group 6 and should have 6 outer electrons
oxygen is in period 2 and should have 2 electron shells
What is the electronic configuration of potassium-39 with a proton number of 19?
How would this change when its ion is formed?
2,8,8,1
it would become
2,8,8
having lost its outer electron to gain a full outer shell and become more stable
Which element has 10 neutrons?
F-19 proton number 9
Ne-20 proton number 10
B-10 proton number 5
Fluorine
19 - 9 = 10 neutrons
What is the electronic configuration of F 1-
Fluroine has a proton number of 9.
2,8
Fluorine is 2,7 but has gained one electron to make F 1-
What is the mass number of Lithium-7 which has 3 protons?
7
Name the parts of an atom
What is the electronic configuration of hydrogen-1 with a proton number of 1.
1
These are the same element, they have the same number of protons but have different number of neutrons. What are they?
They are isotopes
How is a negative ion formed?
A neutral atom gains electrons
What is the octet rule?
Atoms gain or lose electrons to obtain a full outer shell which makes the atom more stable.
Which element will form an ion with charge 3-
Nitrogen found in group 3
Aluminium with 3 outer electrons
sodium found in period 3
Nitrogen, its electronic configuration is 2,5 so it gains 3 electrons to become 2,8 with a charge of 3-
How is a positive ion formed?
The neutral atom must lose electrons.
What is the electronic configuration of Sulfur-32 which has a proton number of 16.
2,8,6
What is the relative mass of a proton, neutrons and electron?
proton 1, neutron 1 - same relative mass
electron (0 or 1/1840)- more of less zero
Which charge ion will this element form?
Chlorine with electronic configuration 2,8,7
It has 7 outer electrons- it will gain one electron and will have the charge 1-
What is the electronic configuration of sodium-23 with a proton number of 11.
2,8,1
Check your answer:
Na is is group 1 and should have 1 outer electron
Which ions can have the electronic configuration
2,8
F 1- and Na 1+
Fluorine is 2,7 but gains one to become 2,8
with a charge of 1-
sodium is 2,8,1 but loses one electron to become 2,8
with a charge of 1+
What is the mass number of an atom?
mass number = number of protons + number of neutrons
What is the electronic configuration of Ca 2+
Calcium has a proton number of 20.
2,8,8
Ca is 2,8,8,2 but Ca 2+ has lost its two outer electrons to gain a full outer shell.
How many neutrons does lithium-7 have?
Lithium has 3 protons
7-3 = 4 neutrons
How many outer electrons does chlorine have?
Which group is chlorine found in?
What is the name of this group?
7 outer electrons
Group 7
Halogens
How do the chemical properties of isotopes compare?
Isotopes have similar chemical properties because they have the same number of outer electrons.
C-12 and C-14 both have 6 protons and 6 electrons but C-14 has 2 more neutrons and is therefore slightly heavier. But they both have 4 outer electrons and behave the same chemically
What is the electronic configuration of chlorine-35 with a proton number of 17?
2,8,7
Check:
Chlorine is in group 7 and should have 7 outer electrons
Chlorine is in period 3 and should have 3 electron shells
What is an isotope?
An atom of the same element with same number of protons and different number of neutrons
