Effective Charge and Trends
The effective nuclear charge (Zeff) experienced by an atom's outer valence electrons is primarily determined and reduced by which type of electrons?
Inner electrons (core electrons).
In J.J. Thomson's experiments, cathode rays were observed to deflect away from a negatively charged electric plate. What did this reveal about the charge of cathode rays?
Cathode rays consist of negatively charged particles (electrons).
What are the specific family names for the elements in Group 1A, Group 6A, and Group 7A, respectively?
Group 1A: Alkali metals; Group 6A: Chalcogens; Group 7A: Halogens.
Which group in the periodic table has the lowest first ionization energy (I1)?
Group 1A (Alkali metals).
On the periodic table, what are the horizontal rows called, and what are the vertical columns called?
Horizontal rows are periods; vertical columns are groups.
In a copper atom (Cu},Z = 29), an electron in which of the following orbitals experiences the greatest effective nuclear charge: 1s, 4s, 4p, or 3d?
1s.
What did Ernest Rutherford's gold foil experiment reveal about the location of mass and subatomic particles in the nuclear model of the atom?
he heavy subatomic particles (protons and neutrons) and virtually all of the atom's mass reside in a dense, central nucleus, while electrons occupy mostly empty space outside the nucleus.
Which of the following elements naturally exists as a diatomic molecule in its elemental form at room temperature: helium, argon, chlorine, phosphorus, or sodium?
Chlorine (Cl2)
Which chemical reaction equation correctly represents the first ionization of neutral oxygen gas?
O(g) > O+(g)+e-
Convert a temperature of 275.18 K to degrees Celsius.
2.03 degrees Celsius.
The elements in the third period of the periodic table all possess a core-electron configuration that is identical to which noble gas?
Neon (Ne).
Give the chemical formula and exact electrical charge for both the hydronium ion and the nitride ion.
Hydronium is H3O+ (charge +1); Nitride is N3- (charge -3).
Which of the following metals does NOT form cations of differing charges (it only forms a single type of cation): Fe, Cu, Na, Sn, or Co?
Na (Sodium).
In general, as you move across a period in the periodic table from left to right:
The atomic radius ________.
The electron affinity becomes ________ negative.
The first ionization energy ________.
(1) Decreases, (2) Increasingly negative, (3) Increases.
Convert 76.234 dm3 into mm3 using the correct number of significant figures.
7.6234 x 107 mm3
Prompt: Consider the following five electron configurations:
(i) 1s2,2s2,2p6,3s1
(ii) 1s2,2s2,2p6,3s2
(iii) 1s2,2s2,2p6,3s2,3p1
(iv) 1s2,2s2,2p6,3s2,3p4
(v) 1s2,2s2,2p6,3s2,3p5
Which configuration belongs to the neutral atom with the highest second ionization energy (I2)?
(i) 1s2,2s2,2p6,3s1
Between the neutral isotope 8036Kr and the neutral isotope 8035Br, which species contains exactly 36 electrons, and how many neutrons does each have?
8036Kr has 36 electrons. 8036Kr has 44 neutrons (80 - 36), while 8035Br has 45 neutrons (80 - 35).
Which of the following chemical substances is classified as an ionic compound: C2H6, NH3, H2O2, or LiBr?
LiBr (Lithium bromide).
Of the elements O, K, B, Na, and S, which has the most negative electron affinity?
S (Sulfur).
A liquid has a density of 2.67 g/cm3. What volume in liters (L) does a 1340 g sample of this liquid occupy?
0.502 L
What is the correct ground-state electron configuration of a neutral silver atom?
[Kr] 5s1 4d10.
An unknown metal element M reacts with fluorine gas to form an ionic compound with the formula MF3. If the metal cation in this compound contains 21 electrons, what is the identity of element M?
Chromium (Cr)
Alkaline earth metals (Group 2A) form ions with what electrical charge, and how does their reactivity with water compare to the alkali metals (Group 1A)?
They exclusively form 2+ ions (M2+); they are less reactive with water than Group 1A metals.
What is the correct full electron configuration for the oxide ion (O2-)?
1s2 2s2 2p6
A pure sample of iron(III) oxide contains 319.4 g of Fe2O3 (molar mass = 159.70 g/mol). How many moles of Fe2O3 are present, and how many total iron (Fe) atoms are contained in the sample? (Use Avogadro's number = 6.022 x 1023)
2.000 mol of Fe2O3; 2.409 x 1024 iron atoms.