Subatomic Showdown
Which subatomic particle has a positive charge?
proton
What is an ion?
An atom that has gained or lost an electron and now has a charge
The atomic number tells you the number of what particle?
protons
What do all elements in the same group (column) have in common?
Same number of valence electrons
What is the name of Group 1 on the periodic table?
Alkali metals
Where are electrons located in an atom?
electron cloud
What happens to the charge of an atom if it gains an electron?
It becomes negative
Draw or describe a simple model of a nitrogen atom (atomic number 7).
Nucleus with 7 protons and 7 neutrons; 2 electrons in first shell, 5 in second.
What increases as you move from left to right across a period?
number of valence electrons
Which family includes fluorine, chlorine, and bromine?
Halogens
What two particles make up the mass number of an atom?
protons & neutrons
A positive ion is called a what?
How many electrons are in the outer shell of a neon atom?
8
Where are the metals located on the periodic table?
left side (left and middle)
Compare the reactivity of Group 1 metals and Group 17 nonmetals.
Both are reactive! Group 1 loses electrons and group 17 gains electrons
An atom has 8 protons, 8 neutrons, and 8 electrons. What is its overall charge?
neutral (0)
What makes carbon-12 and carbon-13 different from each other?
The have different number of neutrons
What does the mass number represent?
Total number of protons and neutrons in the nucleus.
Explain why elements in Group 18 (noble gases) are stable.
They have full outer electron shells
Which family contains elements that have 2 valence electrons?
Alkaline Earth metals
Why do negative electrons stay in orbit around the nucleus?
The nucleus is positively charged and attracts the electrons
A magnesium ion has a +2 charge. Explain how this charge forms in terms of subatomic particles.
Magnesium loses two electrons, leaving it with two more protons than electrons.
How can you use atomic number and mass number to find the number of neutrons? (Use any element as an example.)
Neutrons = Mass number – Atomic number (e.g., Carbon-14 → 14 – 6 = 8 neutrons)
Predict which element is more reactive: lithium (Li) or beryllium (Be)? Explain why.
Lithium because it is an alkali metal with 1 valence electron and Beryllium is an alkaline earth metal with 2 electrons
Compare alkali metals, alkaline earth metals, and halogens in terms of valence electrons and typical reactions.
Alkali metals: 1 valence e⁻, very reactive; Alkaline earth metals: 2 valence e⁻, moderately reactive; Halogens: 7 valence e⁻, very reactive nonmetals.