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Questions

Explanations

1 According to the wave-mechanical model of the atom, an orbital is a region of the most probable location of

(1) an alpha particle (3) an electron

(2) a gamma ray      (4) a proton

2 Which particles have approximately the same mass?

(1) an electron and an alpha particle

(2) an electron and a proton

(3) a neutron and an alpha particle

(4) a neutron and a proton

electrons=1/1836 amu

alpha= 4 amu

3 During a flame test, a lithium salt produces a characteristic red flame. This red color is produced when electrons in excited lithium atoms

(1) are lost by the atoms

(2) are gained by the atoms

(3) return to lower energy states within the atoms

(4) move to higher energy states within the atoms

4 Compared to the energy and charge of the electrons in the first shell of a Be atom, the electrons in the second shell of this atom have

(1) less energy and the same charge

(2) less energy and a different charge

(3) more energy and the same charge

(4) more energy and a different charge

an electron is an electron, so the charge is the same no matter where it is found

5 Which quantity can vary among atoms of the same element?

(1) mass number

(2) atomic number

(3) number of protons

(4) number of electrons

Isotope question- different number of neutrons changes the mass number

6 Which substances have atoms of the same element but different molecular structures?

(1) He_(g) and Ne_(g)      (3) K_(s) and Na_(s)

(2) O_2(g) and O_3(g)       (4) P_4(S) and S_8(S)

both made of oxygen atoms but O₃ is more reactive

7 An atom that has 13 protons and 15 neutrons is an isotope of the element

(1) nickel (3) aluminum

(2) silicon (4) phosphorus

atomic number 13 is Aluminum

8 Which elements have the most similar chemical properties?

(1) Si, As, and Te (3) Mg, Sr, and Ba

(2) N₂, O₂, and F₂ (4) Ca, Cs,and Cu

9 Which list includes three types of chemical formulas for organic compounds?

(1) covalent, metallic, isotopic

(2) covalent, metallic, molecular

(3) empirical, structural, isotopic

(4) empirical, structural, molecular

structural= skeleton you draw

molecular= number of (moles of) atoms in compound

10 In a bond between an atom of carbon and an atom of fluorine, the fluorine atom has a

(1) weaker attraction for electrons

(2) stronger attraction for electrons

(3) smaller number of first-shell electrons

(4) larger number of first-shell electrons

Questions 1-10 Questions 11-20 Questions 21-30 Questions 31-40 Questions 41-50

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