CHEMISTRY COLLEGE

Stars, such as our sun, use fusion to combine hydrogen atoms into helium atoms, and in the process, create energy. As massive stars use the last of their helium fuel, they begin to collapse and temperatures climb high enough to fuse other heavier elements. As elements increase in atomic number, the amount of energy required for fusion to occur also increases. Nickel represents the heaviest element that can be produced by fusion due to to the net energy requirements. Two atoms of ___________ could combine by fusion in order to create nickel. A) hydrogen
B) nitrogen
C) oxygen
D) silicon

Scientists use the emission spectra of elements to detect
A) explosives in luggage.
B) cracks in support structures, like bridges.
C) the possibility of an earthquake occurrence.
D) elements in clouds of gas and dust in deep space

Vanadium has two naturally occuring isotopes - vanadium-50 and vanadium-51. Predict the isotopic mass of vanadium-50 given that vanadium-50 has an abundance of 0.250% and that vanadium-51 has an abundance of 99.750% and a mass of 50.944 amu.
A) 49.944 amu
B) 62.558 amu
C) 63.303 amu
D) 5094.151 amu

Answers

Answer 1
Answer:

Hey there! The answer to your first question is SILICON, Nickle has 28 protons, silicon has 14, 14+14=28. Its the only element thats adds up. I dont know about the 2nd one myself.


Related Questions

MIDDLE SCHOOL

In ____________, electrons are gained by atoms and lost by others. A) ionic bonds
B) covalent bonds
C) metallic bonds
D) polyatomic bonds

Answers

Answer: The correct answer is Option A.

Explanation:

From the given options:

A. Ionic bonds: These bonds are formed when there is complete transfer of electrons from one atom to another atom. An atom which looses electrons is known as electropositive atom and the atoms which gains electrons is known as electronegative atom.

B. Covalent Bonds: These bonds are formed when there is sharing of electrons between the two atoms.

C. Metallic bonds: These bonds are formed from the attraction between the free electrons and fixed positively charged of two metallic atoms.

D. Polyatomic Bonds: These bonds are formed between the species forming a polyatomic ion.

From the given information, the correct answer to this question is Option A.

Answer:

The correct answer here is ionic bond

Explanation:

MIDDLE SCHOOL

What is the chemical formula for flint

Answers

SiO2 is the chemical formula silicon and oxygen
COLLEGE

A 40.15 gram sample of a hydrate of Na2SO4 was heated thoroughly in a porcelain crucible, until its weight remained constant. After heating, 21.27 grams of the anhydrous compound remained. What is the formula of the hydrate?

Answers

Answer:

The formula of the hydrate of the sodium sulfate is :

Explanation:

Mass of hydrated sodium sulfate = 40.15 gram

Mass of completely dehydrated sodium sulfate = 21.27 gram

Mass of water molecules present in hydrated sodium sulfate =x

40.15 gram =  21.27 gram + x (Law of conservation of mass)

x  = 40.15 gram - 21.27 gram = 18.88 g

Moles of water =

Moles of sodium sulfate =

Whole number ratio of sodium sulfate and water:

Sodium sulfate =

Water =

The formula of hydrate be

So, the formula of the hydrate of the sodium sulfate is :

HIGH SCHOOL

There are 3 isotopes of hydrogen and if the average mass of all hydrogen isotopes is 1.0079 amu, which isotope is in greatest abundance in nature?

Answers

Answer:

Protium          

Explanation:

Isotopes -

For some elements , there are various forms possible , which have different number of neutron and same number of protons , are referred to as the isotopes .

The three isotopes possible for the element hydrogen are -

Protium , Deuterium and Tritium .

Where ,

  • Protium has one electron , one proton and zero neutron.
  • Deuterium has one electron , one proton and one neutron.
  • Tritium has one electron , one proton and two neutron.

The most abundant isotope observed is Protium , with 99.98% abundance.

MIDDLE SCHOOL

How do you mix solids?

Answers

Answer:

Liquid–solid mixing is typically done to suspend coarse free-flowing solids, or to break up lumps of fine agglomerated solids. An example of the former is the mixing granulated sugar into water; an example of the latter is the mixing of flour or powdered milk into water.

MIDDLE SCHOOL

Which scientific discipline is correctly matched to a contribution to society?

Answers

The scientific discipline that is correctly matched to a contribution to society would be geology linked to theory of continental drift ecology. Hope this answers the question. Have a nice day.
MIDDLE SCHOOL

How many atoms are in 0.58 mol of Se?​

Answers

Answer: 5. Determine the number of atoms that are in 0.58 mol of Se. 0.58molo se x 6.02x1020 g tors Se - 3.5X1023 atoms Se 1 mol of Se 6.

Explanation:

COLLEGE

Household bleach is an aqueous solution of sodium hypochlorite (NaClO), and its concentration is often measured as a percent by weight. For example, concentrated household bleach has a concentration of 8.25% (w/w), which means there are 8.25 g of NaCl per every 100 g total of solution (NaClO water). For a kinetics experiment, 10 mL of a 5% (w/w) bleach solution was diluted in a 100 mL volumetric flask. 6 mL of this diluted solution is added to 6 mL of dye in a reaction vessel. What is the concentration of bleach (in M) in the reaction vessel

Answers

The  concentration of bleach in the reaction vessel 0.033 M

Concentration:

Given a solution of NaClO with a concentration of 5%w/w:

5% w/w=  5 g NaClO/100 g solution

Now the solution is diluted with 10 ml of the solution to 100 ml.

The resulting concentration after the first dilution:

5%w/w x 10 ml/100 ml = 5% w/w/10= 0.5%w/w

Then 6 ml of 0.5% w/w solution is taken and 6 ml of dye is added to it in a reaction vessel.

The total volume of the solution in the reaction vessel is:

6 ml + 6 ml= 12 ml

Now the resulting concentration of the solution is:

0.5% w/w x 6 ml/12 ml= 0.5% w/w/2= 0.25%w/w

Finally, we need to convert the concentration from %w/w to M (mol solution/1L solution).

Assuming the density of the solution is equal to the density of water (1.00 g/ml) and the molecular weight of NaClO (74.44 g/mol), we get:

0.25 g NaClO/100 g  × 1 mol NaClO/74.44 g ×  1.00 g solution/1 ml ×  100 ml/0.1 L = 0.033 mol/L

concentration = 0.033 M

Learn more about the concentration of a solution:

brainly.com/question/202460?referrer=searchResults

Answer:

The correct answer is 0.033 M

Explanation:

We have a solution of NaClO with a concentration of 5%w/w:

5% w/w=  5 g NaClO/100 g solution

The first dilution is 10 ml of solution in 100 ml. That is a 1/10 dilution (10ml/100 ml= 1/10). That means we are diluting 10 times the solution. We can calculate the resulting concentration after this first dilution as follows:

5%w/w x 10 ml/100 ml = 5% w/w/10= 0.5%w/w

Then, we take 6 ml of 0.5% w/w solution and we add 6 ml of dye in a reaction vessel. The total volume of the solution in the reaction vessel is 6 ml + 6 ml= 12 ml, and we are diluting twice the solution because 6 ml/12 ml= 1/2. We can calculate the resulting concentration of the solution after this second dilution as follows:

0.5% w/w x 6 ml/12 ml= 0.5% w/w/2= 0.25%w/w

Finally, we need to convert the concentration from %w/w to M (mol solution/1L solution). For this, we assume a density of the solution close to the density of water (1.00 g/ml) and we use the molecular weight of NaClO (74.44 g/mol):

0.25 g NaClO/100 g solution x 1 mol NaClO/74.44 g x 1.00 g solution/1 ml x 100 ml/0.1 L= 0.033 mol/L

= 0.033 M

HIGH SCHOOL

4.2g of sodium bicarbonate is equivalent to how many moles of sodium bicarbonate

Answers

The mass of one mole of sodium bicarbonate (aka NaHCO3) is equal to 1 * 22.99g/mol + 1 * 1.00g/mol + 1 * 12.01g/mol + 3 * 16.00g/mol = 83.91g/mol. From this, we can convert 4.2g of NaHCO3 to moles by dividing by 83.91g/mol, to get 0.050 moles of sodium bicarbonate.

Answer: The number of moles of sodium bicarbonate are 0.05 moles.

Explanation:

To calculate the number of moles, we use the equation:

Given mass of sodium bicarbonate = 4.2 g

Molar mass of sodium bicarbonate = 84 g/mol

Putting values in above equation, we get:

Hence, the number of moles of sodium bicarbonate are 0.05 moles.

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