You mean the Circumference and Area of a circle: Circumference is defined by: C = 2*pi*r So C = (2)(22/7)(3.5ft.) C = 22ft. Circumference can also be looked at as perimeter. That means If you walked all the way from starting point to that point again, that would be circumference or perimeter. Area is the … Read more

Again the question says show me an object with four lines of symmetry: Not a reference to it: I will up load the square and then illustrate possible other objects so you are familiar on how to do this on your own.

There are five if it is a true pentagon...the picture that I will upload is a good but not excellent representation of a pentagon...but it reflects the answer to your question. I hope this helps.

If you want to graph Y = 1/2x -2 first understand what the equation means...Y is the value for any given value of x times 1/2 -2 so for x = 1, y = 1/2(1) -2 = 1/2 -2 = -1 1/2  also note that the equation fits the form of Y = mx + b … Read more

The name of a solute-solvent combination is a SOLUTION. Solutes are usually solids that are dissolved by a solvent that the solute is soluble in to make a SOLUTION!.

An oxygen molecule is actually diatomic, an oxygen atom has the count of 16 protons and 16 neutrons. So an oxygen molecule contains two nucleii bringing the proton count to 32 and the neutron to 32, so the as a molecule it has a molecular mass of 32. Oxygen atoms that are unbonded are elements … Read more

One of the most important properties of solutions is evaporation,
is that its vapor pressure lowers (or the number of solvent molecules in gaseous
form decreases) as more solute(salt)is added. In addition to the lower vapor pressure
at the start, as the solvent evaporates, this effect becomes more and … Read more

The color that all items appear are the colors they reflect back at you. When a piece of clothing is observed and it looks red or green any color. These colors are the colors that are not absorbed but reflected. … Read more

The specific heat capacity is usually denoted as Cp or Cv and used as this :

Cp = heat absorbed/increase in temperature per gram(J/Co x gm.)can also be expressed in moles (J/Co x gmMW)(gm MW of substance/moles of substance.) = Cp in units of moles. And this is at constant pressure; the … Read more

The empirical formula is the simplest form; the reduced form of a compound maybe many compounds.

Here are the data; Oxygen O at 94.1% and H at 5.9%
Assume 100grams.

94% = 0.941 x 100gm. = 94.1 gm x 1mole/16gm. = 5.88 moles of O

5.9% = 0.059 x 100gm. = 5.9gm. … Read more

1 1/5 as a percent:

6/5 x 100 = %

1.2 x 100 = 120 % look at the answer to se if it makes sense in a case like this one. With this problem you could almost look at this as two parts.

(1 x 100) + (1/5 x 100) = … Read more

We scientist use statistics to not only analyze data to see if it is statically within certain tolerable error limits, to know how good your data is. To know how your technique is, if experimental error is ruled out , then one can determine the contribution of human error to an experiment. Reproducible data is … Read more

The way that I would tackle this one would first find the Molecular weight of Al2(CO3)3.9H2O:
In this molecule we have:
2 Al atoms:  2 Al atoms = 2 x 26.93 gm. = 53.86
3 C atoms: 3 Carbon atoms = 3 x 12.01 = 36.03
18 O atoms: 18 Oxygen atoms = 18 x 16.00 … Read more

The function of CO2 in  our lives is immeasurable:


Humans use carbon dioxide in many different ways. The   most familiar example is its use in soft drinks and beer, to make them   fizzy. Carbon dioxide released by baking powder or yeast makes cake batter   rise.
  Some fire extinguishers use … Read more

Calculate the [OH-] = 1.6 x 10 -3 M Sr(OH)2

(Ksp= 3.2×10^-4 at 25 °C) A moderately strong hydroxide.

If I use the reaction: Sn(OH)2 --> Sn+2 + 2OH- then in an 1.6 x 10 -3 M solution of Strontium hydroxide the concentration of [OH-] = 2 x 1.6 x … Read more

There are three isomers:

pentane : Straight aliphatic hydrocarbon CH3CH2CH2CH2CH3 Five carbons in length.

Iso-butane or 1-methyl butane  CH3CHCH2CH3
  CH3

2,2 dimethyl-propane   CH3  
… Read more

The easiest and the way you cannot loose is to multiply the number by a fraction = to one.

for instance: 4/4 x 71 = 294/4   or 3/3 x 71 = 213/3 these are technically called fractions. And the fraction retains its past value of 71..I think this is what you are looking for.
… Read more

I would say in between 78-87. That is the average weight for a 10 yr. Old girl who is 54 inches tall.

A 10 year old  (female) child who is 85 pounds  and is 4 feet  and 6 inches tall has a body mass index of 20.5, which is at the 87th percentile, and would indicate that … Read more

I think that "we" as in now are dying whether the earth is here or not. If "we" are available meaning alive:

I have heard it best in this manner:

If you die the world will probably go on as if nothing happened, it will effect your immediate family.

But, if the … Read more

I will discuss the definition of pH and the relationship with the hydrogen ion[H+] supplied by an acid.

By the way: [H+] = moles of [H+]/ 1liter.

Then I will give you one easy and one hard example why the pH equation cannot be your only way of determining whether a substance is … Read more