I am learning chemistry, and i suck at school, i am a B C student which a C is like 80 at me school and usually a 75er for chemistry, but i cant understand this leasson at all, it is dealing with the periods, why the periods cycle, what makes a element a transitional element and so forth, i am going to post my questions and answers for a few, could you please explain them to me and just not the ansewrs thanks :)
1- which of the following elements is a transition metal
calcium, lead, nickel, aluminum
2- complete the sentece, select all that apply

My homework involves a number of masses, ranging between 16.45g and 63.58g, with numerous, random intervals. Each mass represents a can with a cerain number of lead balls it. The objective is to find the mass of a single ball, but it is impossible to tell (at the moment) how many balls are in each can, nor do I know the mass of the can.

The masses are: 16.45g, 16.65g, 16.84g, 16.90g, 24.11g, 24.12g, 27.28g, 27.33g, 38.63g, 38.74g, 41.88g, 42.33g, 42.60g, 45.80g, 49.36g, 49.54g, 60.18g, and 63.58g.
This includes the balls in each can and the can itself.

Please let me know what is the total number of elements present in the periodic table? Some say it is 114, Others say it is 118 . There are still others who claim the number to be 122. Justify your answer giving reasons.

Hi everyone. Im looking for a company that breaks chemicals down to thier original form. I need a powder from a dry chemical extinguisher (Ammonium Sulphate with Silicon Dioxide and Mica) to be broken down so that the silicon dioxide is separated. Basically turning a usless powder going to land fill into a usful powder for farming.
If you know any companys around the world, especially Australia, that may do this please email me on.. dparker_wfsb@yahoo.com.au ... Thanks

In bioinformatics, Basic Local Alignment Search Tool, or BLAST, is an algorithm for comparing primary biological sequence information, such as the amino-acid sequences of different proteins or the nucleotides of DNA sequences. A BLAST search enables a researcher to compare a query sequence with a library or database of sequences, and identify library sequences that resemble the query sequence above a certain threshold.

sulphurous acid reacts with acids and with bases?what about the sulphuric acid?
someone?please:)

I'm trying to complete a homework question. I'll go as far as I've gotten and see if someone can help me farther.

Q: How many grams of sulphuric acid will neutralize 10.0g of sodium hydroxide?

A: H2SO4 + 2 NaOH --> Na2SO4 + 2 H2O
Ratio of 1:2

Molar mass of NaOH (23+16+1)=40g 10g/40g=0.25mol

Molar mass of H2SO4 (2+30.1+64)=96.1g

x/1*0.25/2 = 0.125mol

=0.125mol x 96.1g = 12.3g

Now is where I get stuck. The second part of the question asks:
What volume of water vapour at 100C and 110 kPa would also be produced?

So I'll write what I know so far:
P=110kPa
V= ?

How can we calculate the mean corpuscular Volume (MCV)?
for person who has Hb-8.4g/dl
Haematocrit (Packed Cell Volum ) -26%
Red Blood Cell (RBC or Erythrocyte count ) -3.1x106 ( 10 to the power of 6 )

do we need to convert 26 which is in percente , or do we need to convert mm to leters.

thank you very much in advance.

I need the answer today.

Please Help i am having trouble with my homework and i am falling behind in the class
The problem asks..

Calcium carbonate combines with HCl to produce calcium chloride, water, and carbon dioxide gas. How many moles of HCl are required to react with 2.5 moles of calcium carbonate? How many moles of carbon dioxide would be produced

Please Help

I need help with my stoichiometry homework. the problem says.. 54.0 grams of aluminum react with oxygen. how many grams of aluminum oxide are produced? if anyone could show me how to do the problems thanks...

Scott