All categories

3 years ago

How do I do scientific notation

Chemistry

1 answer:

lina2011 [118]3 years ago

7 0

1. First, move the decimal place until you have a number between 1 and 10. If you keep moving the decimal point to the right in 0.0000073 you will get 7.3.
2. Next, count how many places you moved the decimal point.

You might be interested in

The moons appearance from the earth changes throughout its orbital path because the amount of .... varies ?

Mkey [24]

The amount of reflected sunlight varies. There really isn't any such thing as moonlight. The light we perceive to be produced by the moon is really just sunlight! As the moon moves around the planet, we can see differing amounts of reflected light that we categorize as phases.

I hope this helps! Let me know if you have anymore questions, and have a great day! :)

3 0

3 years ago

How many molecules are found in 90 grams of Al(OH)3?

jarptica [38.1K]

Answer:

6.95 x 10²³ molecules/particles

Explanation:

First we need to find the total Empirical Mass. We can find this by adding each element's mass together.

Al = 26.982,

O = 15.999

H = 1.008

26.982 + 3(15.999) + 3(1.008) = 78.003.

Now we divide by the mass given (90 grams).

90/78.003 = 1.153801777.

We then take that number and multiply it by avogadro's number (6.022 x 10²³)

1.153801777 x avogadro's number = 6.95 x 10²³

6 0

3 years ago

How many molecules are in 3 moles of potassium bromide (KBr)

sattari [20]

Answer:

Your strategy here will be to use the molar mass of potassium bromide,

KBr

, as a conversion factor to help you find the mass of three moles of this compound.

So, a compound's molar mass essentially tells you the mass of one mole of said compound. Now, let's assume that you only have a periodic table to work with here.

Potassium bromide is an ionic compound that is made up of potassium cations,

, and bromide anions,

−

. Essentially, one formula unit of potassium bromide contains a potassium atom and a bromine atom.

Use the periodic table to find the molar masses of these two elements. You will find

For K:

39.0963 g mol

−

For Br:

79.904 g mol

−

To get the molar mass of one formula unit of potassium bromide, add the molar masses of the two elements

M KBr

39.0963 g mol

−

79.904 g mol

−

≈

119 g mol

−

So, if one mole of potassium bromide has a mas of

119 g

m it follows that three moles will have a mass of

moles KBr

⋅

molar mass of KBr



119 g

mole KBr

357 g

You should round this off to one sig fig, since that is how many sig figs you have for the number of moles of potassium bromide, but I'll leave it rounded to two sig figs

mass of 3 moles of KBr

∣

¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯

360 g

∣

−−−−−−−−−

Explanation:

answer: 360 g 

6 0

3 years ago

♦ O people, evidence has come to you from your Lord, and we have sent down to you a clear light ﴾[An-Nisa: 174].

Yuri [45]

Answer:

Qura'an is what makes my day, I read it every morning and it makes me relaxed. I love reading the Qura'an. Do dua for me because I hope I am gonna memorize it after I finish reading it with tajweed.

Explanation:

7 0

3 years ago

Read 2 more answers

A 7.0 g sample of a hydrocarbon (a molecule that has only hydrogen and carbon) is subject to combustion analysis. The mass of CO

Akimi4 [234]

Answer: The empirical formula for the given compound is $CH_2$