Chapter 5 ATOMIC THEORY: THE NUCLEAR MODEL OF THE ATOM

Which of the following statements is/are correct? (1) Electrons and protons have identical masses but opposite charges. (2) Most of an atom's mass is concentrated in a small, positively charged nucleus. (3) Atoms have equal numbers of protons and neutrons.

2

Which of the following statements is/are correct? (1) Electrons and protons have identical masses but opposite charges. (2) Protons and electrons have charges that are equal in magnitude but opposite in sign. (3) The combination of protons and electrons makes up most of the atom's mass.

2

How many protons, neutrons, and electrons are there in 56Fe3+?

26 protons, 30 neutrons, 23 electrons

Calculate the atomic mass of the element having the following distribution of isotopes: 5.8% of 53.9396 u 91.8% of 55.9349 u 2.1% of 56.9354 u 0.3% of 57.9333 u

55.8 uAtomic mass can be calculated using a weighted average. Atomic mass = (%1/100)(Atomic mass1)+(%2/100)(Atomic mass2)+... Atomic mass = (5.8/100)(53.9396 u)+(91.8/100)(55.9349 u)+(2.1/100)(56.9354 u)+(0.3/100)(57.9333 u) = 55.8 u

According to Rutherford, the nucleus of the atom ______. A) orbits around a definite point in space made of neutrinos and electrons B) has a positive charge and contains most of the mass of the atom C) has a neutral charge and contains most of the mass of the atom D) is a definite point in space with a neutral charge E) is not a definite point in space, but rather it is a dense cloud of electrons

B)

Which of the following is not a description of atoms according to Dalton's atomic theory? A) Atoms cannot be destroyed or created B) Atoms of different elements may combine in the ratio of small, whole numbers to form compounds C) Atoms of the same element that have different masses are called isotopes D) All atoms of one element have the same mass E) Atoms of two different elements have different masses

C

Which of the following is a reasonable criticism of the Bohr model of the atom? A) It does not adequately predict the line spectrum of hydrogen. B) It shows the electrons to exist outside of the nucleus. C) It does not adequately predict the ionization energy of the valence electron(s) for elements other than hydrogen. D) It makes no attempt to explain why the negative electron does not eventually fall into the positive nucleus. E) It does not adequately predict the ionization energy of the first energy level electrons for one-electron species for elements other than hydrogen.

C)

An isotope of which of element is chosen as a standard in measuring atomic mass?

Carbon (C - 12)

Mendeleev

Created the first periodic table. Arranged elements by increasing atomic mass

Which of the following is a correct statement about the Rutherford scattering experiment? A) The experiment provided an explanation of the discrete lines in atomic spectra B) The experiment yielded evidence that electrons are charged particles but neutrons are not electrically charged C) The experiment showed that the electrons contain nearly all of the mass of the atom D) The experiment provided evidence that matter does not consist of atoms E) The experiment indicated that at the center of the atom is a tiny and extremely dense nucleus

E)

Which of the following statements are part of John Dalton's atomic theory? I. All atoms of an element are identical in all ways. II. Isotopes have the same number of neutrons but a different number of protons. III. Compounds are always composed of two or more elements. IV. Atoms of different elements are different. V. Compounds are random chemical combinations of several elements.

I, III, and IV

The modern periodic table has the elements arranged in order of increasing ______.

atomic number.

Which of the three major subatomic particles has/have a mass of approximately 1 u? i. e- ii. p+ iii. n0

ii and iii

Oxygen-18

is chemically identical to oxygen-16 .

What is the largest single category or grouping of elements in the periodic table?

metals

The element Erbium, Er, has five abundant isotopes 164Er, 166Er, 167Er, 168Er, and 170Er. The difference among these five isotopes is the ______.

number of neutrons

Mole

the quantity of anything that has the same number of particles found in 12.000 grams of carbon-12.