Classification of Elements and Periodicity Questions and Answers

(a) Estimate the maximum wavelength used for analysis. 550 of visible light absorbed by the purple Co-complex ion that you synthesized c nm; (b) What is the oxidation state of Co in the complex ion?(c) Determine the crystal field splitting energy, A., in units of J/photon and kJ/mol-photons.

List the number of protons, neutrons, and electrons for 40 Ca²+: 40 protons, 20 neutrons, and 20 electrons 40 protons, 20 neutrons, and 18 electrons 20 protons, 20 neutrons, and 18 electrons 20 protons, 20 neutrons, and 22 electrons 60 protons, 20 neutrons, and 18 electrons

A laser used in DVD players has a wavelength of 405 nm. What is the energy of this light in joules? 4.91 × 10^-28 J 4.91 × 10^-19 J 8.05 × 10^-32 J 8.05 x 10^-23 J 2.98 × 10^-32 J

Calculate the molar mass of Fe 3(PO 4) 2. 237.64 g/mol 262.52 g/mol 245.79 g/mol 357.49 g/mol 525.04 g/mol

Use this simulation to explore strong bases and answer the question below. Make sure to explore both the "Molecules" and "Graph" views. Based on this simulation, what is true of bases? Select all that apply. Strong bases have lower pH values than weak bases. When a strong base dissociates, the concentration of the strong base in the solution becomes negligible. Strong bases completely dissociate into M (metal cation) and OH Strong bases dissociate to form more hydroxide ions than a weak base. The products formed when a strong base dissociates can carry out a reverse reaction to form the strong base once more.

Rutherford's scattering experiment demonstrated the existence of protons. the existence of electrons. the existence of neutrons. that most of the mass of an atom is in its nucleus. that the charge-to-mass ratio of an electron is constant.

In any neutral atom the number of electrons equals the number of protons. the number of electrons is less than the number of protons. the number of electrons is greater than the number of protons. the number of electrons is equal to the number of neutrons. the number of neutrons is always equal to the number of protons.

The isotopes of hydrogen show much greater difference in physical properties than are found between the isotopes of the other elements. Which of the following is not correct order? H₂ < D₂ < T₂ (Mass of atom (amu)) H₂ < D2 (Latent heat of fusion) H₂ < D₂ (Latent heat of Vaporization) H₂> D2 > T2 (Magnitude of freezing point (K))

Phosphorus containing organic compound is heated with Na2O2 to give compound A. Compound A is boiled with HNO3 and then treated with ammonium molybdate to give yellow precipitate B. Molecular formula of compound B is (NH4)3[P(M03010)4] (NH4)3[P(M03010)5] (NH4)3[P(M03010)6] (NH4)3[P(M03010)3]

A bottle of soda has a volume of 474 mL. What is this volume in L? 4.74 L 0.474 L 47.4 L 2.11 L 0.00211 L

A characteristic of a substance that involves the transformations the substance can undergo to produce a different substance is a physical property. a chemical property. a physical change. a material property. a characteristic property.

Which is the correct electron configuration of Cu? 1s² 2s² 2p6 3s² 3p6 4s² 4d⁹ 1s² 2s² 2p6 3s² 3p6 4s² 3d⁹ 1s² 2s² 2p6 3s² 3p6 4s² 3d4 1s² 2s² 2p6 3s2 3p6 4s¹ 4d⁹ 1s² 2s² 2p6 3s² 3p6 4s¹ 3d10

Which statement correctly describes the structure of the atom? the electron cloud accounts for the volume and the negative charge the electron cloud accounts for the volume and the positive charge the nucleus contains particles with both positive and negative charges the nucleus accounts for the volume and the negative charge

Electron Configuration: Which of the following is Iron (Fe) electron configuration? 1s2, 2s2, 2p6, 3s2, 3p6 1s2, 2s2, 2p6, 3s2,3p6, 3d2 1s2, 2s2, 2p6, 3s2, 3p6, 3d10 1s2, 2s2, 2p6, 3s2, 3p6, 4s2, 3d6

Which of the following is true about all of the molecules named in this way? They all consist of only two elements. The first element is a metal, and the second is a nonmetal. The number of atoms belonging to either element is not reflected in the compound's name. The name of the metal ion gets an -ide suffix added to it. The name of the nonmetal ion gets an -ide suffix added to it.

Draw the Lewis dot structure for Sr(CN)2. Include all hydrogen atoms and nonbonding electrons. Show the formal charges of all atoms. To change the symbol of an atom, double-click on the atom and enter the letter of the new atom.

Use the periodic table to give the name or symbol for each of the following elements. The halogen in the same period as the alkali metal with 11 protons The alkaline earth metal in the same period with the neutral noble gas with 18 electrons The noble gas in the same period as gold

A closed vessel of fixed volume contains 22.9 g of CO₂(g) exerting a pressure of 1.50 atm. Some CH4(g) is introduced into the vessel, increasing the pressure to 3.25 atm. What mass of CH4(g) (in grams) was introduced in the vessel? Enter your answer in decimal notation, rounded to 3 significant figures.

Problem: (Practice exam Q.20) Which of the following statements is true? a) H₂O has a greater dipole moment than H₂S b) H₂O is a polar, but H₂S is non-polar c) Both H₂O and H₂S have zero dipole moments d)Both H₂O and H₂S are linear

(6 pts) The molarity of a NaOH solution is 1.72x10-10 M. 4a. Calculate the [OH-], [H+], pOH, pH. Need to write the answers with one digit after the decimal for the pOH and pH. For the [OH-] and [H], the answers must be in scientific notation with one digit after the decimal. Must show all your work. Do not use scratch paper. Do the work directly on your paper. 4b)This solution is (acidic, basic, or neutral). (select the correct answer). Briefly explain.

Assume that Potassium Iodide and Lead(II) Nitrate are the starting substances (reactants) in a reaction: a. Write a balanced chemical reaction between Potassium Iodide and Lead(II) Nitrate. Be sure to include physical states. b. State the names of the products that are produced from this reaction. c. Write complete ionic and net ionic reactions for the balanced equation in part (a). d. What type of reaction(s) is/are being represented by the chemical reaction you wrote in part (a)? e. If 9.2 g of potassium iodide and 1.8 g of lead(II) iodide are combined then theoretically, what mass of solid product could be formed from these amounts of reactants? What is the limiting reactant? f. What is the % yield if 3.550 g of the solid product was actually obtained? g. Based on your answers to parts (a) - (f), determine whether a solid precipitate forms in the reaction. h. How many potassium atoms are in 0.227 g of potassium iodide? i. How many moles of lead(II) nitrate will react with 0.887 mg of potassium iodide? j. How many molecules are in one mole of lead(II) nitrate?

PI3Cl2 is a nonpolar molecule. Based on this information, determine the I-P-I bond angle, the CI-P-Cl bond angle, and the I-P-Cl bond angle. Enter the number of degrees of the I-P-I, CI-P-Cl, and I-P-Cl

How many grams of PbBr₂ will precipitate when excess CrBr₂ solution is added to 51.0 mL of 0.657 M Pb(NO3)2 solution? Pb(NO3)2(aq) + CrBr₂(aq) → PbBr₂(s) + Cr(NO3)2(aq)

What is true of an acidic solution? An acidic solution contains more hydronium ions than hydroxide ions. An acidic solution contains the same number of hydronium ions as hydroxide ions. An acidic solution contains more hydroxide ions than hydronium ions. An acidic solution contains more OH ions than H3O+ ions.

If you dissolve 10.0 g of compound X in 100.0 mL of distilled water, the liquid turns red. The temperature of the liquid stays at 24 °C for 10 minutes. Why would you not want to sell a cold pack made with compound X?

Hydrogen atoms emit light with a wavelength of 410.2 nm when the electron transitions from the n = 6 level to a final quantum state. Associate each of the quantities in this question with a variable and/or constant in an equation from your equation sheet. What is the sign associated with the change in energy of this transition? What is the value of ΔE? What is the quantum number of this final state (nf)?

The percent by mass of fluorine in PNF2 is

1. How many ATOMS of sulfur are present in 2.55 moles of sulfur dioxide ? 2. How many MOLES of oxygen are present in 3.89x1022 molecules of sulfur dioxide ?

Na + H₂O → NaOH + H₂ This chemical reaction represents the reaction of sodium, Na, in water, H₂O, to produce sodium hydroxide, NaOH, and hydrogen gas, H₂. When correctly balanced, the coefficient for sodium hydroxide, NaOH, is_____ A. 2 B. 4 C. 1 D. 3

Ba(CIO3)2 BaCl2 + O₂ This chemical reaction represents the decomposition of barium chlorate (Ba(CIO3)2) into barium chloride (BaCl₂) and oxygen gas. When correctly balanced, the coefficient for oxygen will be ____ A. 1 B. 5 C. 3 D. 6

Aluminium and nitrogen react to form an ionic compound called aluminium nitride. These show the electron arrangement for the two elements: a. Answer these questions for an aluminium atom. i. Does it gain or lose electrons, to form an ion? ii. How many electrons are transferred? iii. Is the ion formed positive, or negative? iv. What charge does the ion have? b. Now repeat a, but for a nitrogen atom. c. Give the electron distribution for the ions formed by the two atoms. (2 + ...) ii. What do you notice about these distributions? Explain it. d. Name another non-metal that will form an ionic compound with aluminium, in the same way as nitrogen does.

How many atoms are in 4.91 g of magnesium? Select the correct answer below: A. 1.22 x 10^23 atoms B. 2.96 x 10^24 atoms C. 2.98 x 10^24 atoms D. 1.46 x 10^25 atoms

A hypothetical ionic compound has the following formula: AB2 Which option shows the most likely periodic table groups for the elements A and B? A. A: Group 2, B: Group 17. B. A: Group 2, B: Group 18. C. A: Group 1, B: Group 18. D. A: Group 1, B: Group 17.

A hypothetical ionic compound has the following formula: A3 B2 Which option shows the most likely periodic table groups for the elements A and B? A. A: Group 1, B: Group 16. B. A: Group 2, B: Group 15. C. A: Group 2, B: Group 16. D. A: Group 1, B: Group 15.

An atom of an unknown element can gain 3 electrons to reach a full octet. How many valence electrons does an atom of this element have? A. 2. B. 4. C. 3. D. 5.

Predict the ordering, from shortest to longest, of the bond lengths in CO, CO2, and CO32- Rank from shortest to longest.

Draw a single Lewis structure for the phosphate ion (PO43), assuming that the phosphorus atom can expand its octet such that the formal charge on each of the atoms is minimized. Include all formal charges and lone-pair electrons.

The element calcium is in group ___ and period ___ The element thallium is in group ___ and period ___ The element titanium is in group ___ and period ___

Selenium exists in several isotopic forms, including 34Se76, 34Se77, and 34Se78. Choose the number of protons and the number of neutrons in each of these isotopes. (Select all that apply.) 34Se77 (43 protons, 34 neutrons) 34Se78 (34 protons, 44 neutrons) 34Se76 (34 protons, 42 neutrons) 34Se76 (42 protons, 34 neutrons) 34Se77 (34 protons, 43 neutrons) 34Se78 (44 protons, 34 neutrons)