How many mililiters is 0.55 L

Calculate the number of atoms in 2.0g of hydrogen atoms?

Jobisdone [24]

First you calculate how many moles there are in 2.0 grams of hydrogen (H2) atoms.
Hydrogen has a relative atomic mass (RAM) of 1 g/mol, but there are 2 hydrogen atoms: 1 x 2 = 2 g/mol

To work out how many moles there are,
use the formula: n(moles) = mass ÷ molar mass
n(moles) = 2 grams ÷ 2 g/mol = 1 mol

Then use Avogadro's Constant : 6.023 x 10^23
= 1 x 6.023 x 10^23
= 6.023 x 10^23

Final step is to multiply it by the number of atoms, in this case there are 2.
= 6.023 x 10^23 x 2
= 12.046 x 10^23
= 1.205 x 10^24

that ^ should be your final answer

have a great day :)

4 0

3 years ago

The prefix ‘kilo-‘ means a thousand.

Blababa [14]

Answer:

0.97 kg, 1.0kg

Explanation:

As you have mentioned in the question, to convert kilo-gram to grams, this conversion is used, 1 kilogram = 1,000 grams

Initially, when one has to convert from one unit to another, there is a lot of confusion. To avoid any such, multiply and divide the number with units to which it has to be converted.

Here,

970 g = $970 g \times\frac{1 kg}{1 kg}$

This makes no difference to the number.

970 g = $970 g \times\frac{1 kg}{1000 g}$

As, 1 kg= 1,000 g

970 g = $\frac{970}{1000} kg$

970 g = 0.97 kg

Rounding this off to the nearest tenth of a kilogram.

The tenths place is immediately to the right of the decimal point.

Here, 9 is at the tenth's place. Round the tenth's place up if the digit at hundredth's place is greater than or equal to 5. Since, 7 > 5, up the number at tenth's place.

So, answer is 1.0 kg

8 0

3 years ago

What is an energy source produced from nuclear reactions

valkas [14]

Answer:

I believe it would be electricity.

Explanation:

6 0

3 years ago

Calculate the mass of 0.25 mole of carbon dioxide

Fantom [35]

Answer:

11 g

Explanation:

1 mole of carbon dioxide =44 g

therefore for 0.25 mole = x

x = 44 × 0.25

x = 11.00g

7 0

3 years ago

A radioactive nucleus alpha decays to yield a sodium-24 nucleus in 14.8 hours. What was the identity of the original nucleus?

Rudik [331]

Answer:

2813Al

Explanation:

You know that alpha decay takes place when a α-particle is being ejected from the nucleus of a radioactive isotope.An

α-particle is simply the nucleus of a helium-4 atom. A helium-4 atom has a total of two protons and two neutrons in its nucleus, and two electrons surrounding that nucleus.

In that case, if a α-particle is the nucleus of a helium-4 atom, then it must have a mass number equal to 4, since it has two protons and two neutrons, and a net charge of (2+) since it no longer has the two electrons that the helium-4 atom has.

So, you know that an unknown radioactive isotope decays via alpha decay to yield a sodium-24 nucleus.

A sodium-24 nucleus contains 11 protons and 13 neutrons. This means that you can write

AZX→2411Na+42α

Here A and Z represent the unknown element's mass number and atomic number, respectively.

So, if you take into account the fact that mass number and atomic number must be conserved in a nuclear reaction, you can say that

A=24+4 and Z=11+2

The unknown isotope will thus have

{A=28Z=13

A quick look at the periodic table will show you that the element that has 13 protons in its nucleus is aluminum, Al. This means that you're dealing with aluminum-28, an isotope of aluminum that has 15 neutrons in its nucleus.

The complete nuclear equation will be

2813Al→2411Na+42α

5 0

4 years ago