Atomic Structure
Where are protons, neutrons, and electrons located in an atom? (It will be two different locations. One subatomic particle goes in a basic area and the other two in a specific one.)
Electrons-Electron Cloud
Periods on the periodic table run in which direction: horizontally or vertically?
Horizontally
Which particle determines the identity (element) of an atom and why?
Protons determine the identity of an element because the number of protons equals the atomic number
Which family forms ions with charge -1 and is not lustrous, ductile, or malleable?
Halogens.
Identify which subatomic particle’s change produces a charged ion, and state whether losing electrons makes a positive or negative ion.
Changing electrons produces ions. Losing electrons → positive ion (cation); gaining electrons → negative ion (anion)
How many electrons does a neutral chlorine atom have?
17 electrons
Which element is most electronegative: helium, neon, fluorine, or francium?
Fluorine.
Which statement best defines an ion?
Ion definition: Atoms of the same element with the same number of protons but a different number of electrons (charged particle).
— Which of these elements is a metalloid: Aluminum (#13), Silicon (#14), Phosphorus (#15), Sulfur (#16)?
Metalloid among choices: Silicon (#14). Silicon shows properties intermediate between metals and nonmetals (semiconductor behavior, partial luster but brittle).
An element has 4 energy levels and commonly forms a +2 ion. Which element is most likely (choose from Ca, C, P, Si) and justify your choice.
Element with 4 energy levels and commonly forms +2: Calcium (Ca). Reason: Ca is in period 4 (four energy levels) and group 2 (forms +2 ions by losing two valence electrons).
How many protons does magnesium have?
12 protons.
— Rank these elements from smallest to largest atomic radius: Boron (B), Aluminum (Al), Nickel (Ni).
From smallest to largest atomic radius: Boron (B) < Aluminum (Al) < Nickel (Ni)
Which statement best defines an isotope? Explain why isotopes cause the atomic mass on the periodic table to show decimals.
Isotope definition: Atoms of the same element with the same number of protons but a different number of neutrons. Isotopes cause the atomic mass to be a decimal because the listed atomic mass is a weighted average of the masses of all naturally occurring isotopes.
Which of these would conduct electricity and heat: Aluminum (#13), Phosphorus (#15), Sulfur (#16), Argon (#18)?
Electrically and thermally conductive: Aluminum (#13). Aluminum is a metal and conducts heat and electricity.
A student claims the atomic number can be larger than the atomic mass. Explain why that claim is incorrect using definitions of atomic number and atomic mass.
— Explain how to calculate the number of neutrons in an atom, and compute the neutrons for an element with atomic number 76 and atomic mass 194.1 (round atomic mass appropriately)
Number of neutrons = rounded atomic mass − atomic number.
For atomic number 76 and atomic mass 194.1: round 194.1 → 194; neutrons = 194 − 76 = 118.
Rank Copper (Cu), Sulfur (S), and Barium (Ba) from least to greatest ionization energy.
Least to greatest ionization energy: Ba < Cu < S.
Reason: Ionization energy increases left→right and up a group. Barium (Ba, an alkaline earth metal, low IE) is lowest; Copper (Cu, transition metal) is intermediate; Sulfur (S, nonmetal) has highest IE of the three
The nitrogen ion has a charge of -3. Explain what happened to the number of electrons
Nitrogen ion with charge −3 (N3−)
Choose two elements from the same family/group, name the family, then list two similarities and two differences between them (chemical or physical).
Many answers. Mrs. A will have checked.
Given an element with atomic number 38 and atomic mass 74.329 (as in Hoopsteride example), calculate the expected number of neutrons (show rounding step), then explain whether the atomic mass decimal could indicate isotopes.
Given atomic number 38 and atomic mass 74.329:
The decimal in atomic mass indicates the element’s atomic mass is a weighted average of isotopes; it does not mean fractional neutrons exist in any single nucleus.
A fictional element “Hoopsteride” shows atomic number 38 and atomic mass 74.329. Calculate protons, neutrons, and electrons for a neutral Hoopsteride atom.
Compare and contrast electronegativity and ionization energy. For each: define what it measures, describe how the trend moves across a period and down a group.
You discover element #119. Predict the ionic charge it would most likely form and explain your reasoning using its position on the periodic table and valence electron count.
Describe where element #119 would be placed on the periodic table: give its period and group, the number of energy levels, and explain how to determine its valence electrons using its position.
Construct a short answer: Explain how electronegativity, ionization energy, and atomic radius are related. Give one real-world example (material or reaction) where these properties explain behavior (e.g., why sodium reacts with chlorine to form NaCl).