General Chemistry Answers

 Compare and contrast the 7 crystal system. 

Find the distance (in nm) between the body-centered atom and one corner atom in Na, given a=0.424 nm.

Sodium crystallizes in the body-centered cubic structure with a=0.424 nm. Calculate the theoretical density of Na in kg/m3 . 

Austenite form of iron has FCC crystal lattice structure, whereas its alpha form has BCC crystal lattice structure. Assuming closest packed arrangement of iron atoms, what will be the ratio of density of Austenite to that of alpha iron?

An element crystallizes in a body-centered cubic lattice. The edge of the unit cell is 0.286 nm, and the density of the crystal is 7.92 g/cm3 . Calculate the atomic weight of the element.

Using concrete examples, give an account on what links and delinks Biochemistry to and from:                                                                                                       

   a)        Biology. 

   b)     Chemistry.

Li has two naturally occurring isotopes, 6

Li (isotopic mass 6.0151 amu) and 7

Li (isotopic mass 7.0160 amu).

Calculate the percentage abundance of each isotope if the atomic mass of lithium is 6.941 amu.

Isotopes: This contains isotopes. Remember that an isotope is atoms of the same element that have different numbers of neutrons. Fill in the missing blanks.

Isotope

Name

Isotope Symbol

Atomic Number

Mass Number

# of Protons

# of Neutrons

# of Electrons

11.calcium-40

12.uranium-238

13.potassium-40

14.Identify the number of different elements each of the following molecules contains.

a.   H2O has ? elements

b.   HCl has ? elements

c.    NaOH has ? elements

d.   C6H10O2N4 has ? elements

15. Identify the total number of atoms in each of the following:

a.   CO has ? atoms

b.   Co has ? atoms

c.    H2O has ? atoms

d.   KBr has ? atoms

e.   H2SO4 has ? atoms

f.     H2 has ? atoms

g.   2H has ? atoms