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3 years ago

Which two celestial bodies orbit the Sun?

Chemistry

2 answers:

tiny-mole [99]3 years ago

7 0

Number 1 is Comets and asteroids
Number 2 is Comets are made of ice and rock
Number 3 is Meteor

Illusion [34]3 years ago

4 0

1.<span>comets and asteroids
2.comets are made of ice and rock
3.meteor</span>

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Fill In the blank:<br> Compression is the part of the medium where particles are ________.

STALIN [3.7K]

Compressed is the answer!

I hope this helps. :)

7 0

4 years ago

Carbon-14 has a half-life of 5,730 years. If scientists discover a mummified Cro-Magnon specimen, they will first want to determ

ryzh [129]

Answer:

the specimen has 11460 years old

Explanation:

if the live sample has as initial amount of Yo C14, the dead sample will have 0.25Yo of C14.

the rate of decay of radiactive matter over time is

Y(t) = Yo * e (( - t * Ln2 ) / T)

∴ Y(t) = 0.25Yo; T = 5730

⇒ 0.25Yo = Yo * e (( - t * Ln2 ) / 5730 )

⇒ 0.25 = e (( - t * Ln2 ) / 5730 )

⇒ Ln(0.25) = ( - t * Ln2 ) / 5730

⇒ - 7943.466 = - t * Ln2

⇒ 7943.466 / Ln2 = t

⇒ t = 11460 year

4 0

3 years ago

6 How many moles are in a 321 g sample of magnesium?

Tatiana [17]

Answer:

13.4mol of Mg

Explanation:

Given parameters:

Mass of magnesium = 321g

Unknown:

Number of moles = ?

Solution:

The number of moles of a substance is given as;

Number of moles = $\frac{mass}{molar mass}$

Molar mass of Mg = 24g/mol

Insert the parameters and solve;

Number of moles = $\frac{321}{24}$ = 13.4mol of Mg

3 0

3 years ago

Which property describes the shininess of an element?

goldenfox [79]

Answer: Metals are shiny and lustrous with a high density. They have very high melting and boiling points because metallic bonding is very strong, so the atoms are reluctant to break apart into a liquid or gas.

Explanation:

sorry for not answering in less than 1 minute

6 0

3 years ago

Read 2 more answers

How much potassium chloride is needed to make 0.500 m solution with 1.50 L of water?

Andrew [12]

Answer:

55.9 g KCl.

Explanation:

Hello there!

In this case, according to the definition of molality for the 0.500-molar solution, we need to divide the moles of solute (potassium chloride) over the kilograms of solvent as shown below:

$m=\frac{mol}{kilograms}$

Thus, solving for the moles of solute, we obtain:

$mol=m*kilograms$

Since the density of water is 1 kg/L, we obtain the following moles:

$mol=0.500mol/kg*1.50kg\\\\mol=0.75mol$

Next, since the molar mass of KCl is 74.5513 g/mol, the mass would be:

$0.75mol*\frac{74.5513g}{1mol}\\\\55.9g \ KCl$

Regards!

4 0

3 years ago