Atomic structure Questions and Answers

To measure the amount of nickel In some industrial waste fluid, an analytical chemist adds 0.3600M sodium hydroxide (NaOH) solution to a 22.0 g sample of the fluid and collects the solid nickel(II) hydroxide (Ni(OH)₂) product. When no more Ni(OH)₂ is produced, she filters, washes and weighs It, and finds that 379. mg has been produced. The balanced chemical equation for the reaction is: Ni²+ (aq) + 2NaOH(aq) → Ni(OH)₂(s) + 2 Na* (aq) What kind of reaction is this? If you said this was a precipitation reaction, enter the chemical formula of the precipitate. If you said this was an acid-base reaction, enter the chemical formula of the reactant that is acting as the base. If you said this was a redox reaction, enter the chemical symbol of the element that is oxidized. Calculate the mass percent of Ni in the sample.

Copper is a common metal with many important uses, including power generation and building construction. A copper pipe fitting has a mass of 19.7 g and a strand of heavy-duty copper wire has a mass of 84.3 g. Which has the smaller specific heat? Which has the smaller heat capacity? A small piece of an unknown metal has the same mass as a copper pipe fitting (19.7 g). Each piece of metal absorbs the same amount of heat and the copper pipe fitting undergoes a larger increase in temperature. Which has the larger specific heat? If both pieces of metal are cooled in a refrigerator and undergo the same decrease in temperature, which will undergo the larger change in thermal energy?

How many molecules of H₂O are equivalent to 97.2 g H₂O? (H = 1.008 g/mol, O = 16.00 g/mol) Enter your answer with the correct number of significant figures and be sure the prefix is a number between 1 and 10!

In a different experiment, a student places a piece of pure Ba (s) in a beaker containing 250. mL of 6.44 M HCl (aq) and observes that the rate of appearance of H₂(g) bubbles when Ba(s) was added is much faster than the rate of appearance of bubbles when the Mg(s) was added. The student claims that the greater reactivity is due to the difference in ionization energy between Mg and Ba. Explain the difference in ionization energy between Mg and Ba in terms of atomic structure.

A compound with a molecular mass of 56.104 grams is found to be 86% carbon. The rest of the compound is hydrogen. Find its molecular formula. C4H8 C₂H4 C6H10 C3H6

Which of the following elements has a luster and is malleable and ductile? Cu C O Kr

Which is a correct comparison between the modern quantum model and John Dalton's model of the atom? The modern model is not as widely accepted by scientists as Dalton's model. The modern model states that atoms of all elements are identical, whereas Dalton's model does not. The modern model recognizes particles in the atom, whereas Dalton's model does not. The modern model does not explain emission spectra, whereas Dalton's model does.

In the normal atomic models given by Rutherford and Bohr, we assume that nucleus is stationary and electron revolves round in it with uniform speed. The motion of electron prevents it from dropping into the nucleus against the electrostatic attraction between nucleus and electron. If nucleus is attracting electron, electron is also attracting the nucleus. To prevent this attraction, nucleus should also revolve with uniform speed. What change it will create in the calculation made for position, speed, time period, energy, etc of electron ? the mass of electron should be replaced by the reduced mass. the mass of electron should not be replaced by the reduced mass. There is no effect of any kind by considering nuclear motion. the mass of electron should be replaced by the reduced mass if nucleus remains stationary.

When a metal is exposed to 5.92×102 nm orange radiation, it emits an electron with kinetic energy 0.00342 eV. What is the threshold frequency for this metal? (1.000 eV = 1.602×10-19 J) Provide your answer in E-notation rounded to three significant figures. 5.06x1014 Hz 3.35x10-19 Hz 5.06x1023 Hz 5.06x105 Hz 3.35x10-10 Hz

GeCl SeCl4 ICI4- ICl4+ The species represented above all have the same number of chlorine atoms attached to the central atom. (a) Draw the Lewis structure of each of the four species. Show all valence electrons in your structures. (If a charge is shown, put them in brackets with the charge outside the brackets.) (b) Identify the bond angle, shape, hybridization for each compound.

Using Bohr's description of electron energy predict the amount of energy required to excite our electron in hydron from the ground state to a very high energy level (n = 10).

An unknown compound has the following chemical formula: NxO where x stands for a whole number. Measurements also show that a certain sample of the unknown compound contains 5.9 mol of nitrogen and 5.92 mol of oxygen. Write the complete chemical formula for the unknown compound.

X-ray radiation falls in the wavelength region of 1.00×10-11 to 1.00×10-8 meters. What is the energy of X-ray radiation that has a wavelength of 1.00x10-11 m?

A local AM radio station broadcasts at a frequency of 616 kHz. Calculate the wavelength at which it is broadcasting.

Suppose you need 6.5 m of Grade 70 tow chain, which has a diameter of 3/8" and weighs 2.16 kg/m, to tow a car. How would you calculate the mass of this much chain? Set the math up. But don't do any of it. Just leave your answer as a math expression. Also, be sure your answer includes all the correct unit symbols.

Using only the periodic table arrange the following elements in order of increasing ionization energy:

This energy diagram shows the allowed energy levels of an electron in a certain atom. (Note: the SI prefix 'zepto' means 10-21. You can find the meaning of any SI prefix in the ALEKS Data tab.)

Re-order each list in the table below, if necessary, so that the atoms or ions in it are listed in order of decreasing size.

Propylene is made by polymerizing propene. How many molecules of propene must be polymerized to make 3.50g of polypropylene? 6.02E23 Cannot be determined because the molar mass of polypropylene is not provided. 2.11E24 1.43E22 5.01E22

Which of the following is not part of Dalton's atomic theory? All matter is composed of small indivisible particles called atoms. All atoms of a given element have identical mass and chemical properties. Atoms of one element can be changed to atoms of another element in a chemical reaction. Atoms combine in whole-number ratios to form chemical compounds. Chemical reactions involve a rearrangement of the atoms in the starting materials.

During a flame test, a potassium salt produces a characteristic purple flame. This purple color is produced when electrons in excited potassium atoms are a lost by the atoms b gained by the atoms c returned to lower energy states within the atoms

High-dose-rate temporary brachytherapy (another name for sealed source radiotherapy) is used to treat some head and neck cancers. Brachytherapy uses a radioisotope that is sealed in either a protective capsule or wire and placed next to or inside the area being treated. The capsule or wire allows the ionizing radiation to escape and destroy the nearby cancer cells, while keeping the radioisotope from moving within the tissue. In temporary brachytherapy, the radioactive source is removed from the patient after a short period of time. Suppose that iridium-192 is applied to a tumor for 6.5 min. What is the atomic number of iridium?

Which element is represented by the following electron configuration? 1s²2s²2p63s23p² Silver (Ag) Silicon (Si) Sodium (Na) Selenium (Se)

A scientist in another universe (identical in all respects to our own except for the value of Planck's constant), shines electromagnetic radiation of wavelength 2.00 x 10-1 m on a metal with a work function of 9.25 x 10-19 J. Electrons are ejected from the metal, but their maximum kinetic energy is zero. What is the value of Planck's constant as determined from this experiment? 6.63 x 10-34 J.s 2.63 x 10-28 J.s 6.17 x 10-28 J.s 3.57 x 10-28 J.s

Which one of the following statements regarding periodic properties is FALSE? Li has a higher electron affinity that F. O has a lower first ionization energy than N. Br atoms are smaller than As atoms. Mg has a lower effective nuclear charge than P.

If the wavelength of a photon is 689 nm, a) what is the frequency? b) What is the energy?

A light source with a frequency of 1.8 x 1015 s-1 is introduced to a metal which has a work function of 5.9 x 10-19 J. How much energy does the exiting electron have? What part of the electromagnetic radiation does the energy belong to? microwave gamma radio UV IR

What is the wavelength associated with a transition of an electron from n=6 to n=3 ?

What is the energy of a hydrogen electron when it "resides" in the n-4 level?

The Pauli exclusion principle requires that both the position and momentum of the electron cannot be known simultaneously very accurately. an electron can have either particle property or wave property. no two electrons in the same atom can have the same set of four quantum numbers. when filling orbitals of similar energy, an electron must fill each orbital before being paired.

Listed below are the first and second ionization energies for potassium and calcium. Use this information to answer the next 2 questions. (Support and justify your answers)

Give the set of four quantum numbers that represent the last electron added to the Zn atom.

Which of the following statements is NOT true? The Heisenberg uncertainty principle states that it is impossible to determine accurately both the position and velocity of an electron. Rutherford's alpha particle scattering experiment demonstrated that most of the mass of an atom is in a small dense nucleus. The solution of Schrodinger's wave equation permits you to predict the exact location and momentum of a hydrogen atom's electron at any time. de Broglie reasoned that matter could have both wave and particle properties.

Write abbreviated electron configuration for tellurium (Te, Z = 52) and answer the questions that follow: (Include your electron configuration in your work upload and answer questions below directly into Canvas. a) How many electrons in this atom have n = 5? b) How many electrons in this atom occupy d orbitals? c) How many electrons in this atom occupy s orbitals?

Given the photon emission of an electron relaxation from an atom is 505.8 nm. What is the frequency (in THz) of this photon? Given the speed of light is 3.00 × 108 m/s. (1 nm = 10-9 m and 1 THz = 1012 Hz)

The energy emitted by relaxation of an electron from an excited state to a lower state of nf = 2 is 5.01 x 10-19 J. Determine the energy level (n) associated with this relaxation. Given RH = 2.18 × 10-18 J.

3.55b Menthol, the substance we can smell in mentholated cough drops, is composed of C, H, and O. A 0.1005-g sample of menthol is combusted, producing 0.2829 g of CO2 and 0.1159 g of H2O. What is the empirical formula for menthol? If menthol has a molar mass of 156 g>mol, what is its molecular formula?

Consider the stable nuclei for carbon and bromine. Which nucleus would you predict has the same number of protons and neutrons?

The wavelike properties of a baseball thrown at 1 m-s1 cannot be observed because of which of the following? A. Because its wavelength is too short B. Because its frequency is too low. C. Because of the uncertainty principle D. Because its kinetic energy is too small E. Because its wavelength is too long