Molecules .
A) are named according to the alphabet
B) are the smallest units of matter
C) must be made of two different elements
D) are made of two or more atoms

D

Explanation:

A is incorrect because they are named by elements and the number of atoms.

B is incorrect because the smallest units of matter are usually considered to be atoms.

C is incorrect because O2 is considered a molecule, and is made of only one element.

So, D is correct, because molecules are groups of two or more atoms that are held together by chemical bonds.

in theory, limestone is composed principally of the compound calcium carbonate - caco3, but in reality this compound is deposited in conditions involving a number of other compounds as impurities so it ends up being a mixture of many compounds.

hope this : -)

tony (lordcaos066)

consider the reaction below.

 no rx

at 500 k, the reaction is at equilibrium with the following concentrations.

[pci5]= 0.0095 m

[pci3] = 0.020

[ci2] = 0.020 m

what is the equilibrium constant for the given reaction?

0.042

0.42

2.4

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