What is the density of an object having a mass of 4.0 g and a volume of 30 mL?

Which of the following is unchanged at the end of the CNO cycle?

Musya8 [376]

Answer:

The correct option is: A. carbon-12

Explanation:

The CNO cycle, the abbreviation for the carbon-nitrogen-oxygen cycle, is a catalytic cycle by which the stars produce helium from elemental hydrogen, via a series of nuclear fusion reactions.

This cycle involves the fusion of four protons with carbon ( $_{6}^{12}\textrm{C}$ ), nitrogen isotope ( $_{7}^{13}\textrm{N}$ ), and oxygen isotope ( $_{8}^{15}\textrm{O}$ ), to give an alpha particle and two electron neutrinos and positrons.

The reaction involves the regeneration of carbon ( $_{6}^{12}\textrm{C}$ ) nucleus in the last step.

$_{6}^{12}\textrm{C}$ → $_{7}^{13}\textrm{N}$ → $_{6}^{13}\textrm{C}$ → $_{7}^{14}\textrm{N}$ → $_{8}^{15}\textrm{O}$ → $_{7}^{15}\textrm{N}$ → $_{6}^{12}\textrm{C}$

3 0

2 years ago

What is the empirical formula of a compound that is 24.42 % calcium, 17.07 % nitrogen, and 58.5% oxygen?

REY [17]

Answer:

$CaN_{2} O_{6}$

Explanation:

When calculating an empirical formula from percentages, assume you have a 100g sample. This allows you to convert the percentages directly to grams, because X % of 100g is X grams.

So:

24.42 % = 24.42 g Ca, 17.07% = 17.07g N, 58.5% = 58.5g O

The next step is to divide each mass by their molar mass to convert your grams to moles.

24.42/40.08 = 0.6092 mol

17.07/14.01 = 1.218 mol

58.85/15.99 = 3.680 mol

Then you will divide all of your mol values by the SMALLEST number of moles. This gives you whole numbers that are the mole ratio (subcripts) of the empircal formula.

0.6092 mol/0.6092 mol = 1

1.218 mol/0.6092 mol = 2

3.680 mol/0.6092 mol = 6

So the empirical formula is $CaN_{2} O_{6}$

5 0

2 years ago

Which of the following phases of matter has a fixed shape and volume

kodGreya [7K]

A matter in the solid phase has a fixed shape and volume.

4 0

2 years ago

Read 2 more answers

In your own words, please describe the difference between a complete ionic equation and a net ionic equation.

beks73 [17]

Explanation:

In the molecular equation for a reaction, all of the reactants and products are represented as neutral molecules (even soluble ionic compounds and strong acids). In the complete ionic equation, soluble ionic compounds and strong acids are rewritten as dissociated ions.

The net ionic equation is a chemical equation for a reaction that lists only those species participating in the reaction. The net ionic equation is commonly used in acid-base neutralization reactions, double displacement reactions, and redox reactions.

6 0

2 years ago

Which of the following is most likely to be covalent?<br> MgO <br> CO <br> CaO <br> BaO

Kisachek [45]

Answer:

CaO

Explanation:

CaO is the only compound that is a non-metal and a non-metal. The rest of the compounds are ionic, or metal and non-metal.

8 0

2 years ago