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3 years ago

What elements make up the sun?

1 answer:

5 0

72 percent is hydrogen. Nuclear fusion converts hydrogen into other elements. The sun is also composed of about 26 percent helium and trace amounts of other elements; oxygen, carbon, neon, nitrogen, magnesium, iron and silicon.

http://www.space.com/17170-what-is-the-sun-made-of.html

You might be interested in

What volume of a 0.160 MM solution of KOHKOH must be added to 550.0 mLmL of the acidic solution to completely neutralize all of

puteri [66]

The given question is incomplete. The complete question is :

What volume of 0.160 M solution of KOH must be added to 550.0 mL of the acidic solution to completely neutralize all of the 0.150 M hydrochloric acid?

Answer: Volume in liters to three significant figures is 0.516 L

Explanation:

To calculate the volume of acid, we use the equation given by neutralization reaction:

$n_1M_1V_1=n_2M_2V_2$

where,

$n_1,M_1\text{ and }V_1$ are the n-factor, molarity and volume of acid which is $HCl$

$n_2,M_2\text{ and }V_2$ are the n-factor, molarity and volume of base which is KOH

We are given:

$n_1=1\\M_1=0.50M\\V_1=550.0mL\\n_2=1\\M_2=0.160M\\V_2=?$

Putting values in above equation, we get:

$1\times 0.150\times 550.0=1\times 0.160\times V_2\\\\V_2=516mL=0.516L$ (1L=1000ml)

Thus volume in liters to three significant figures is 0.516 L

6 0

3 years ago

[20pts] I want to start counterfeiting American pennies. Each penny weighs 2.56g and I want $200.00 of pennies for my scheme. Se

Lera25 [3.4K]

Answer:

$\$200.00\times 100\dfrac{penny}{\$}\times \dfrac{2.56g}{penny}\times \dfrac{1molCu}{63.5gCu}\times \dfrac{2molAl}{3molCu}\times \dfrac{27gAl}{1molAl}$

Explanation:

The dimensional analysis helps you by focusing your attention into the units: you must set up the equation starting with the available units and add the factors with the units such that the cancelation of numerators and denominators ends up with the desired units: grams of aluminium in this case.

In this case, you start with a mass of 2.56 grams per penny, which is $2.56g/penny$ , whose value is $200.00 and want to end with the grams of

Aluminium needed.

Then, you must use the mole ratios derived from the chemical equation in a way that the units lead from grams of copper to grams of aluminium.

The equation is:

$2Al(s)+3CuCl_2(aq)\rightarrow 2AlCl_3(aq)+3Cu(s)$

From which, the mole ratio between copper and aluminium is:

$2molAl(s):3molCu(s)\\\\\dfrac{2molAl}{3molCu},or\\\\\\\dfrac{3molCu}{2molAl}$

You must also use the atomic masses of Cu and Al which are 63.5g/mol and 27g/mol respectively.

The equation is:

$\$200.00\times 100\dfrac{penny}{\$}\times \dfrac{2.56g}{penny}\times \dfrac{1molCu}{63.5gCu}\times \dfrac{2molAl}{3molCu}\times \dfrac{27gAl}{1molAl}$

You can check that afeter multiplying all the factors, the most units will cancel and the final units will be grams of Al.

8 0

3 years ago

K-40 is a radioactive isotope of potassium that undergoes beta decay. What is the product of this decay

Aleks [24]

Answer:

⁴⁰₂₀Ca + ⁰₋₁e

Explanation:

Beta decay:

Beta radiations are result from the beta decay in which electron is ejected. The neutron inside of the nucleus converted into the proton an thus emit the electron which is called β particle.

Properties of beta radiations:

The mass of beta particle is smaller than the alpha particles.

They can travel in air in few meter distance.

These radiations can penetrate into the human skin.

The sheet of aluminium is used to block the beta radiation

⁴⁰₁₉K → ⁴⁰₂₀Ca + ⁰₋₁e

The beta radiations are emitted in this reaction. The one electron is ejected and neutron is converted into proton.

5 0

3 years ago

At 293 K, methanol has a vapor pressure of 97.7 Torr and ethanol has a vapor pressure of 44.6 Torr. What would be the vapor pres

Bad White [126]

Answer: The vapor pressure of a mixture of 80 g of ethanol and 97 g of methanol at 293 K is 78.3 torr.

Explanation:

According to Raoult's law, the vapor pressure of a component at a given temperature is equal to the mole fraction of that component multiplied by the vapor pressure of that component in the pure state.

$p_1=x_1p_1^0$ and $p_2=x_2P_2^0$