New York State Earth Science RegentsNew York State Living Environment Regents

 
New York State Chemistry Regents January 2008
Chemistry Regents January 2008 - Question 01 PDF Print E-mail
Written by The Chemistry Wizard   

chemjan08q(1)
(1) atomic number is the correct answer.

An atom’s atomic number is the number of protons found in an atom.  It uniquely identifies a chemical element. 
The other choices cannot identify an element because these properties can be shared by other elements, so they are not unique properties.

 
Chemistry Regents January 2008 - Question 02 PDF Print E-mail
Written by The Chemistry Wizard   

chemjan08q (2)

(2) lithium atom is the correct answer.

The atomic number tells you the number of electrons; in this case, lithium has three electrons, so its first orbital contains 2 electrons and its

second orbital is only partially filled because it only contains 1 electron.

 
Chemistry Regents January 2008 - Question 03 PDF Print E-mail
Written by The Chemistry Wizard   

chemjan08q (3)

(3) +7 is the correct answer.

The atomic number of nitrogen is 7, so its nucleus is composed of 7 protons and seven neutrons.  (7 electrons surround the nucleus).  Because each proton carries a positive charge and neutrons are neutral, the nucleus carries a charge of +7.

 
Chemistry Regents January 2008 - Question 04 PDF Print E-mail
Written by The Chemistry Wizard   

chemjan08q (4)

(2) atomic mass is the correct answer.

The atomic mass depends on the average of the isotopes of the element; for this reason, it is not a whole number.  The atomic number is

constant and the same for all isotopes, so it is not affected by the relative abundance.

 
Chemistry Regents January 2008 - Question 05 PDF Print E-mail
Written by The Chemistry Wizard   

chemjan08q (5)

(2) 12 atomic mass units is the correct answer.

An atomic mass unit (Dalton) is the approximate mass of a hydrogen atom, a proton, or a neutron.  Electrons have a very small mass relative

to protons and neutrons.

 
Chemistry Regents January 2008 - Question 35 PDF Print E-mail
Written by The Chemistry Wizard   

chemjan08q (35)

(4) 310 g/mol is the correct answer.

In order to calculate gram formula mass, you simply need to count the number of atoms in the compound and refer to the molar masses on your periodic table.

In this compound there are 3 Ca atoms (3 x 40), 2 P atoms (2 x 31), and 8 O atoms (8x16). 
120 + 62 + 128 = 310 g/mol.

 
Chemistry Regents January 2008 - Question 36 PDF Print E-mail
Written by The Chemistry Wizard   

chemjan08q (36)

(2) neon, only

Although argon and neon are in the same column of the periodic table, they have different electron configurations.

The configuration of argon is : 1s^2 2s^2 2p^6 3s^2 3p^6

And the configuration of neon is: 1s^2 2s^2 2p^6

This question tests your knowledge in the difference between electron configuration and valence electrons (in this case argon and neon are the same).  Remember that the ions formed by NaF are more similar to neon (and located between Na and F on the periodic table) than they are to argon.

 
Chemistry Regents January 2008 - Question 53 PDF Print E-mail
Written by The Chemistry Wizard   

chemjan08q (53)

2-7-4-1

2-7-5

You can see this shortened version comes from the longer normal electron configuration for silicon which is:1s2 2s2 2p6 3s2 3p2

This can also be written as 2-8-4; however, when the silicon atom is excited, an electron travels from the 2nd to the third shell or from the 2nd to the fourth shell.

Last Updated on Friday, 13 March 2009 10:15
 
Chemistry Regents January 2008 - Question 55 PDF Print E-mail
Written by The Chemistry Wizard   
chemjan08q (55)You can see the total number of protons and neutrons in the atom and the number of electron shells.
Last Updated on Monday, 09 March 2009 07:10
 
Chemistry Regents January 2008 - Question 56 PDF Print E-mail
Written by The Chemistry Wizard   
chemjan08q (56)The mass number of magnesium is 23, or the sum of protons and neutrons.
 
<< Start < Prev 1 2 Next > End >>

Page 1 of 2

Copyright Information

All works and materials contained within this site Copyright © 2009 Technology Strategies For Success

Disclaimer

We are not affiliated with, nor endorsed by, the New York State Education Department.

The information contained in this website is for general information purposes only. The information is provided by "Technology Strategies for Success" and while we strive to keep the information up-to-date and correct, we make no representations or warranties of any kind, express or implied, about the completeness, accuracy, reliability, suitability or availability with respect to the website or the information, products, services, or related graphics contained on the website for any purpose. Any reliance you place on such information is therefore strictly at your own risk.