Periodic Trends Flashcards: Atomic Radius, Ionization Energy & Electronegativity
Review 88 concise cards on atomic and ionic radius, shielding, effective nuclear charge, ionization energy, electron affinity, electronegativity, metallic character, exceptions, and comparisons.
Despre acest pachet
Periodic Trends Flashcards: Atomic Radius, Ionization Energy & Electronegativity
Study the core periodic trends with 88 independently written English flashcards for high-school and introductory-college chemistry. The deck separates broad patterns from the reasons behind them and uses generally where real configurations create exceptions.
What the cards practice
The sequence covers four useful recall paths: term to definition; table movement to a general property direction; cause to effect through shell number, shielding, distance, and effective nuclear charge; and a concrete pair or isoelectronic set to the expected comparison. Atomic and ionic radius, first and successive ionization energies, electron affinity, electronegativity, metallic character, and selected reactivity links are all included.
The course-level exceptions are deliberately small: Be versus B, Mg versus Al, N versus O, P versus S, and Cl versus F electron affinity. Electron-affinity wording distinguishes a favorable electron gain from the sign convention used by a source. Electronegativity stays tied to bonded atoms, and ionic-radius comparisons state when an isoelectronic rule applies.
Learning order
Definitions and table structure come first. General directions follow, then causal models, ion-size rules, successive-ionization reasoning, limited exceptions, and applied comparisons. Related prompts are spaced apart in a fixed order; the review scheduler handles longer-term interleaving after installation.
Scope
This deck teaches qualitative periodic-trend reasoning. It excludes exact numerical property tables, memorizing values for all 118 elements, advanced transition-metal irregularities, diagonal relationships, melting and boiling trends, broad group trivia, and copied examination or competitor material. It supports chemistry practice but does not replace calculation, laboratory, or full-course problem solving.
Sources and license
Core trends and explanations were checked against OpenStax Chemistry: Atoms First 2e, section 3.5 and its electronegativity discussion in section 4.2. Terminology was cross-checked against the IUPAC Gold Book entries for ionization energy, electron affinity, and electronegativity.
The prompts, answers, examples, organization, metadata, and generated cover were created independently from common chemistry knowledge and original work. No protected cards, textbook prose, source figures, exact property tables, logos, or third-party media were copied.
The Common knowledge · CC0 1.0 label applies only to the original prompts, answers, examples, organization, metadata, and cover, to the extent applicable rights exist. It does not claim ownership of scientific facts or third-party material.
Source review date: August 29, 2026.
Fișele din acest pachet
Fișa 1
Întrebare
What is a periodic trend?
Răspuns
A recurring pattern in element properties as atomic number increases across periods and down groups.
Fișa 2
Întrebare
What does covalent radius measure?
Răspuns
Half the distance between the nuclei of two identical atoms joined by a covalent bond.
Fișa 3
Întrebare
What is first ionization energy?
Răspuns
The minimum energy needed to remove the most loosely bound electron from an isolated gaseous atom in its ground state.
Fișa 4
Întrebare
What is electronegativity?
Răspuns
An atom's ability to attract shared electrons toward itself in a chemical bond.
Fișa 5
Întrebare
What is a period on the periodic table?
Răspuns
A horizontal row. For main-group elements, moving across a period fills orbitals in the same principal electron shell.
Fișa 6
Întrebare
What is ionic radius?
Răspuns
A measure of an ion's size, usually inferred from distances between ions in crystals.
Fișa 7
Întrebare
What does electron affinity describe?
Răspuns
The energy change when an electron is added to an isolated gaseous atom to form a gaseous anion.
Fișa 8
Întrebare
What does metallic character describe?
Răspuns
How readily an element shows metallic behavior, especially losing valence electrons and forming cations.
Fișa 9
Întrebare
What is a group on the periodic table?
Răspuns
A vertical column. Main-group elements in one group usually share a valence-electron pattern and similar chemistry.
Fișa 10
Întrebare
What is effective nuclear charge?
Răspuns
The net positive pull an electron feels from the nucleus after shielding and electron–electron repulsion are taken into account.
Fișa 11
Întrebare
What are successive ionization energies?
Răspuns
The energies needed to remove electrons one after another from the same atom, then from its increasingly positive ions.
Fișa 12
Întrebare
How does electronegativity difference relate to bond polarity?
Răspuns
A larger difference generally produces a more uneven electron distribution and a more polar bond.
Fișa 13
Întrebare
Why do main-group elements in one group often behave similarly?
Răspuns
They have the same general number and arrangement of valence electrons, which drive much of their bonding and reactivity.
Fișa 14
Întrebare
What is electron shielding?
Răspuns
The reduction in nuclear attraction felt by an electron because other electrons lie between it and the nucleus and repel it.
Fișa 15
Întrebare
Why does the definition of ionization energy specify a gaseous atom?
Răspuns
It isolates the atom from bonding and intermolecular effects, so the energy reflects electron removal from that species itself.
Fișa 16
Întrebare
Where are metals and nonmetals generally found on the periodic table?
Răspuns
Metals occupy the left and center; nonmetals cluster toward the upper right, with metalloids near the boundary.
Fișa 17
Întrebare
What changes in the electron arrangement across a main-group period?
Răspuns
Electrons are added to the same principal shell while the nucleus gains one proton from one element to the next.
Fișa 18
Întrebare
How does atomic radius generally change from left to right across a period?
Răspuns
It decreases.
Fișa 19
Întrebare
How does first ionization energy generally change from left to right across a period?
Răspuns
It increases, although a few recurring subshell and electron-pairing exceptions interrupt the rise.
Fișa 20
Întrebare
How does electronegativity generally change from left to right across a period?
Răspuns
It increases for the elements normally assigned electronegativity values.
Fișa 21
Întrebare
What changes in the electron arrangement down a main-group group?
Răspuns
Each step adds a higher principal electron shell while preserving a similar valence-electron pattern.
Fișa 22
Întrebare
How does atomic radius generally change down a group?
Răspuns
It increases.
Fișa 23
Întrebare
How does first ionization energy generally change down a group?
Răspuns
It decreases.
Fișa 24
Întrebare
How does electronegativity generally change down a group?
Răspuns
It decreases.
Fișa 25
Întrebare
How does effective nuclear charge generally change across a main-group period?
Răspuns
It increases because nuclear charge rises while added electrons enter the same principal shell and do not fully shield one another.
Fișa 26
Întrebare
How does a cation's radius compare with its neutral parent atom?
Răspuns
The cation is smaller.
Fișa 27
Întrebare
How does electron addition generally change across a period?
Răspuns
It generally becomes more energetically favorable toward the right, but electron affinity has substantial exceptions and depends on the sign convention used.
Fișa 28
Întrebare
How does metallic character generally change from left to right across a period?
Răspuns
It decreases.
Fișa 29
Întrebare
Why are valence electrons generally farther from the nucleus down a group?
Răspuns
They occupy shells with higher principal quantum numbers, so the electron cloud extends farther outward.
Fișa 30
Întrebare
How does an anion's radius compare with its neutral parent atom?
Răspuns
The anion is larger.
Fișa 31
Întrebare
How does favorable electron addition generally change down a group?
Răspuns
It generally becomes less favorable as the added electron enters a larger, more shielded shell, though electron-affinity irregularities are common.
Fișa 32
Întrebare
How does metallic character generally change down a group?
Răspuns
It increases.
Fișa 33
Întrebare
Why does shielding change less than nuclear charge across a main-group period?
Răspuns
The added electrons enter the same principal shell, so they do not shield one another as effectively as inner-shell electrons do.
Fișa 34
Întrebare
Which has the larger atomic radius, Li or Na?
Răspuns
Na. It lies below Li and has an additional occupied electron shell.
Fișa 35
Întrebare
Which has the larger atomic radius, Na or Mg?
Răspuns
Na. Atomic radius generally decreases from left to right across Period 3.
Fișa 36
Întrebare
How does greater electron–nucleus distance affect electrostatic attraction?
Răspuns
It weakens the attraction, all else being equal.
Fișa 37
Întrebare
How do successive ionization energies for one element compare?
Răspuns
Each successive ionization energy is higher than the one before it because an electron is removed from an increasingly positive species.
Fișa 38
Întrebare
Which has the higher first ionization energy, Li or Na?
Răspuns
Li. Its valence electron is closer to the nucleus and less shielded.
Fișa 39
Întrebare
Which has the higher first ionization energy, Na or Mg?
Răspuns
Mg. Its greater effective nuclear charge holds the valence electrons more tightly.
Fișa 40
Întrebare
Why does forming a cation usually shrink an atom?
Răspuns
Electron loss reduces electron–electron repulsion and increases the nuclear pull per remaining electron; losing the outer shell can shrink it sharply.
Fișa 41
Întrebare
Which element is most electronegative on the Pauling scale?
Răspuns
Fluorine.
Fișa 42
Întrebare
Which is more electronegative, Li or Na?
Răspuns
Li. Electronegativity generally decreases down Group 1.
Fișa 43
Întrebare
Which is more electronegative, Na or Mg?
Răspuns
Mg. Electronegativity generally increases across Period 3.
Fișa 44
Întrebare
What does a large jump between successive ionization energies reveal?
Răspuns
The next electron would come from a lower, core shell; the number removed before the jump indicates the valence-electron count for a main-group atom.
Fișa 45
Întrebare
Why is Cl⁻ larger than neutral Cl?
Răspuns
The added electron increases repulsion within the valence shell while the nuclear charge stays the same.
Fișa 46
Întrebare
How do you compare the radii of isoelectronic species?
Răspuns
The species with more protons is smaller because the same number of electrons feels a stronger nuclear attraction.
Fișa 47
Întrebare
Why does an atom have no single sharp physical radius?
Răspuns
Its electron cloud has no hard edge, so atomic size depends on a defined measurement such as covalent, metallic, or van der Waals radius.
Fișa 48
Întrebare
Why are noble-gas electronegativities often omitted in introductory tables?
Răspuns
Electronegativity describes attraction in a bond, and many noble gases form too few ordinary bonds for a standard value to be useful on common scales.
Fișa 49
Întrebare
Why does forming an anion usually expand an atom?
Răspuns
The extra electron increases electron–electron repulsion and lowers the nuclear pull available per electron.
Fișa 50
Întrebare
Order O²⁻, F⁻, and Ne from largest to smallest radius.
Răspuns
O²⁻ > F⁻ > Ne. All have 10 electrons, and increasing proton count pulls that electron cloud inward.
Fișa 51
Întrebare
After which removal does Na show its first large ionization-energy jump?
Răspuns
After the first electron. Removing one valence electron leaves a stable core, so the second removal reaches that core.
Fișa 52
Întrebare
Does electronegativity difference create a universal ionic-versus-covalent cutoff?
Răspuns
No. A larger difference usually means more bond polarity, but bonding lies on a continuum and context matters.
Fișa 53
Întrebare
How do noble gases generally differ from halogens in electron affinity?
Răspuns
Adding an electron to a noble gas is generally unfavorable because it must begin a higher-energy shell; halogens usually gain one much more favorably.
Fișa 54
Întrebare
Which is smaller, Na⁺ or Mg²⁺?
Răspuns
Mg²⁺. Both have 10 electrons, but Mg²⁺ has one more proton.
Fișa 55
Întrebare
After which removal does Mg show its first large ionization-energy jump?
Răspuns
After the second electron. Mg has two valence electrons, so the third removal reaches a core shell.
Fișa 56
Întrebare
How does electronegativity differ from electron affinity?
Răspuns
Electronegativity is a relative measure of attraction for shared electrons in a bond; electron affinity is an energy change for adding an electron to an isolated gaseous species.
Fișa 57
Întrebare
How are atomic radius and first ionization energy generally related?
Răspuns
A larger radius usually means a lower first ionization energy because the valence electron is farther from the nucleus and easier to remove.
Fișa 58
Întrebare
Which has the more exothermic first electron affinity, F or Cl?
Răspuns
Cl. Fluorine's very compact 2p shell creates stronger electron–electron repulsion for the incoming electron, so this pair breaks the simple down-group expectation.
Fișa 59
Întrebare
Which has the higher first ionization energy, Be or B?
Răspuns
Be. B loses a higher-energy 2p electron, while Be loses a more penetrating 2s electron from a filled 2s subshell.
Fișa 60
Întrebare
Why does Group 1 metal reactivity generally increase down the group?
Răspuns
The valence electron is farther out and more shielded, so its first ionization energy falls and electron loss becomes easier.
Fișa 61
Întrebare
How are atomic radius and electronegativity generally related?
Răspuns
Smaller atoms usually attract bonding electrons more strongly, so electronegativity tends to rise as radius falls.
Fișa 62
Întrebare
Why is Na⁺ much smaller than neutral Na?
Răspuns
Na loses its entire third-shell valence level, leaving the smaller neon-like electron configuration.
Fișa 63
Întrebare
Which has the higher first ionization energy, Mg or Al?
Răspuns
Mg. Al's removed electron is a higher-energy 3p electron, while Mg loses a more penetrating 3s electron from a filled 3s subshell.
Fișa 64
Întrebare
Why does halogen reactivity generally decrease down Group 17?
Răspuns
Larger radius and greater shielding weaken attraction for an incoming electron, so oxidizing ability generally falls. Particular reactions still depend on bond energies and conditions.
Fișa 65
Întrebare
Why do Groups 2 and 15 often interrupt the simple electron-affinity trend?
Răspuns
Group 2 has a filled s subshell and Group 15 has a half-filled p subshell, so an added electron enters a less favorable arrangement.
Fișa 66
Întrebare
Can ion charge alone rank two unrelated ionic radii?
Răspuns
No. Shell number, electron count, proton count, oxidation state, and crystal environment can all matter; the isoelectronic rule needs the same electron count.
Fișa 67
Întrebare
Which has the higher first ionization energy, N or O?
Răspuns
N. Its half-filled 2p subshell is relatively stable; O has one paired 2p orbital, and repulsion makes one electron easier to remove.
Fișa 68
Întrebare
In which direction does nonmetallic character generally increase?
Răspuns
Up and to the right, opposite the general trend in metallic character.
Fișa 69
Întrebare
Within the same principal shell, which penetrates closer to the nucleus: an s or p orbital?
Răspuns
An s orbital. Greater penetration means its electrons are less shielded and usually lower in energy than p electrons in the same shell.
Fișa 70
Întrebare
How do same-charge ion radii generally change down a group?
Răspuns
They increase as occupied electron shells are added.
Fișa 71
Întrebare
Which has the higher first ionization energy, P or S?
Răspuns
P. Its half-filled 3p subshell is relatively stable; S contains a paired 3p orbital that increases repulsion and eases removal.
Fișa 72
Întrebare
Why should simple periodic-direction rules be used cautiously for transition metals?
Răspuns
d-electron filling, shielding, oxidation state, and contraction effects make their property changes less regular than main-group trends.
Fișa 73
Întrebare
Why do periodic-trend statements usually say “generally”?
Răspuns
Subshell energies, electron pairing, radius definitions, and element-specific configurations create real exceptions to the broad patterns.
Fișa 74
Întrebare
Which has the larger atomic radius, K or Br?
Răspuns
K. Both are in Period 4, and atomic radius generally decreases from left to right.
Fișa 75
Întrebare
Which has the higher first ionization energy, Mg or Cl?
Răspuns
Cl. Its valence electrons experience greater effective nuclear charge and are held more tightly.
Fișa 76
Întrebare
Which is more electronegative, Al or Si?
Răspuns
Si. Electronegativity generally increases across Period 3.
Fișa 77
Întrebare
Which has the larger atomic radius, O or F?
Răspuns
O. Atomic radius generally decreases across Period 2.
Fișa 78
Întrebare
Which has the higher first ionization energy, K or Br?
Răspuns
Br. First ionization energy generally increases across Period 4.
Fișa 79
Întrebare
Which is more electronegative, Mg or Cl?
Răspuns
Cl. It lies farther right in Period 3.
Fișa 80
Întrebare
Which has the larger atomic radius, Al or Si?
Răspuns
Al. Atomic radius generally decreases across Period 3 as effective nuclear charge rises.
Fișa 81
Întrebare
Which has the higher first ionization energy, O or F?
Răspuns
F. This pair follows the general increase across Period 2.
Fișa 82
Întrebare
Which is more electronegative, K or Br?
Răspuns
Br. Electronegativity generally increases across Period 4.
Fișa 83
Întrebare
Which has the larger atomic radius, Mg or Cl?
Răspuns
Mg. Both are in Period 3, and Mg lies farther left.
Fișa 84
Întrebare
Which has the higher first ionization energy, Al or Si?
Răspuns
Si. This pair follows the general increase across Period 3.
Fișa 85
Întrebare
Which is more electronegative, O or F?
Răspuns
F, the most electronegative element on the Pauling scale.
Fișa 86
Întrebare
Order Al³⁺, Mg²⁺, Na⁺, Ne, F⁻, and O²⁻ from smallest to largest radius.
Răspuns
Al³⁺ < Mg²⁺ < Na⁺ < Ne < F⁻ < O²⁻. All have 10 electrons, so radius grows as proton count falls.
Fișa 87
Întrebare
Why do upper-right nonmetals usually hold valence electrons tightly?
Răspuns
Their relatively small radii and high effective nuclear charges create strong attraction between the nucleus and valence electrons.
Fișa 88
Întrebare
Across a main-group period, what shared cause links smaller radius, higher ionization energy, and higher electronegativity?
Răspuns
Increasing effective nuclear charge pulls the same-shell valence electrons inward and holds them more strongly.
88 de fișe
Periodic Trends Flashcards: Atomic Radius, Ionization Energy & Electronegativity
Nibomo se deschide ca să poți începe să studiezi.