June 2013 Chemistry Regents #1-10

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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

3 link electrons are located in orbitals

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

4 link protons and neutrons=1 amu

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

3 link excited electrons fall to lower energy levels releasing energy in the form of light

 

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

3 link electrons in higher energy levels have higher energy...

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

1 link atom implies neutrality, so protons and electrons must always be equal when the word atom appears

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) O2(g) and O3(g)       (4) P4(S) and S8(S)

2 link O2(g) and O3(g) oxygen gas and ozone

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

3 link protons =atomic number

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

3 link similar properties, same group

 

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

4   empirical= lowest ratio

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

2 link electronegativity question- fluorine has the greatest attraction for electrons in a bond

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

Question 51-53 Questions 54-56 Questions 57-59 Questions 60-62 Questions 63-65 Questions 66-69 Questions 70-73 Questions 74-77  Questions 78-80  Questions 81-82  Questions 83-85

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