an air sample consists of 99.6% of nitrogen-14 and 0.4% of nitrogen-15. what is the average mass of nitrogen in this sample?

Independent atoms have high potential energy,and they are highly unstable.

And when they form bonds their potential energy decreases and they become stable.

Hence bonded atoms are stable and have relatively low potential energy than independent atoms.

A compound contains atoms of different elements chemically combined together in a fixed ratio. An element is a pure chemical substance made of same type of atom. Compounds contain different elements in a fixed ratio arranged in a defined manner through chemical bonds.

The properties of the compound are different from the properties of the elements that make it up.

When elements combine in a specified ratio, compounds are formed. These compounds differ markedly from the elements that compose them.

As elements combine to form compounds, the individual properties of the combining elements are no longer observed. Only the properties of the compound formed is now observed.

Hence, the properties of the compound are different from the properties of the elements that make it up.

Learn more: https://brainly.com/question/11067389

1) The overall balanced photosynthesis reaction:  

6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂.

Plants convert solar energy into the chemical energy of sugars (food).

2) Chemical reaction of cellular respiration:  

C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O.

Organic carbon (glucose) is transformed into inorganic carbon (carbon dioxide) that goes into atmosphere.

3) Gasoline combustion:

C₈H₁₈ + 25/2O₂ → 8CO₂ + 9H₂O.

Gasoline is a mixture of many different hydrocarbons: alkanes (paraffins), cycloalkanes and alkenes (olefins).

Gasoline is being burn.

4) Balanced chemical reaction of forming rust: 4Fe + 3O₂ → 2Fe₂O₃.

Forming rust usually last for few months and iron changing in another substance with different properties.

5) An electrochemical cell (voltaic or galvanic cell) is generating electrical energy from chemical reactions.  

In galvanic cell, specie (for example zinc and zinc cations) from one half-cell, lose electrons (oxidation) and species from the other half-cell (for example copper and copper cations) gain electrons (reduction).  

Oxidation on the zinc anode: Zn(s) → Zn²⁺(aq) + 2e⁻.

Reduction on the copper cathode: Cu²⁺(aq) + 2e⁻ → Cu(s).

Copper is forming from the solution, that is chemical change.

6) Balanced chemical reaction: CaO + H₂O → Ca(OH)₂.

Making limewater  (diluted solution of calcium hydroxide).

7) Neutralization is reaction in which an acid and a base react quantitatively with each other. In this reaction, there are no acids and bases, only salts.

Balanced chemical reaction of vinegar and antacid:

2CH₃COOH(aq) + Mg(OH)₂(aq) → (CH₃COO)₂Mg(s) + 2H₂O(l).

Precipation is formed.

8) Balanced chemical reaction of magnesium and hydrochloric acid:

MgO + 2HCl → MgCl₂ + H₂O(g).

Acid dissolves metal oxides.

9) Chemical reaction of silver in air:

4Ag + 2H₂S + O₂ → 2Ag₂S (tarnish) + 2H₂O.

Silver change color in the air.

10) Forming of patina: 2CuO + CO₂ + H₂O → Cu₂CO₃(OH)₂.

Brass (copper) change color to green.

Answer is: 2. exothermic.

There are two types of reaction:  

1) exothermic reaction (chemical reaction that releases more energy than it absorbs).  

For example, ΔH(reaction) = -225 kJ/mol; this is exothermic reaction.

2) endothermic reaction (chemical reaction that absorbs more energy than it releases).

Hydrogen peroxide (H₂O₂):

1) have molecular structure.

2) it is higly reactive, it is not physically and chemically stable.

3) has low boiling point (around 150°C), because weak covalent bonds.

4) dissolve in water, because it has polar bond.

Answer is: the average net change in temperature is 4°C.

the average net change = the average high - the average low.

the average net change = -6°C - (-10°C).

the average net change = 4°C.

Temperature is the intensity of heat present in a substance and a thermometer is a device that measures temperature or a temperature gradient.

The Celsius scale was based on 0°C for the freezing point of water and 100°C for the boiling point of water at 1 atm pressure.

The average net change in temperature in Nuuk in January, from the high to the low, is 4 degrees Celsius. This is determined by subtracting the average low temperature from the average high temperature.

In Nuuk, the average net change in temperature in January from high to low is calculated by subtracting the average low temperature from the average high temperature. Therefore, with an average high of -6 Celsius and an average low of -10 Celsius, the net change is 4 degrees Celsius. This is a routine method for determining the daily temperature range in a specific location, particularly useful in meteorology and climatology studies.

https://brainly.com/question/16555548

#SPJ3

Sb2 as a standalone molecule is unusual. While Antimony (Sb) usually forms a trigonal pyramidal molecule, the exact structure and polarity depend on the other atoms in the molecule.

The geometry name for Sb2 seems to be incorrect as it is unusual for antimony (Sb) to form a molecule with itself. Assuming it was intended to be SbF3 or similar, antimony typically forms bonds that result in a trigonal pyramidal molecular structure due to the electron geometry and polar bonds. However, the correct molecular structure and polar/non-polar status depends on the other atoms in the molecule.

As per the reference, antimony can form antimony(III) sulfide, which is also known as Sb2S3. Antimony typically has an oxidation state of +3 or +5 as it has 5 valence electrons, meaning in most of its compounds, it will form 3 covalent bonds and leave 2 electrons unshared, resulting in a trigonal pyramidal shape with sp³ hybridization, which will likely be a polar molecule due to the unequal sharing of electrons between Sb and other atoms.

https://brainly.com/question/503958

#SPJ3

valance refers to the total number of electrons that exist in the orbitals that occupy the outermost energy level of an atom. you pretty much got it!

B is a double replacement reaction where OH and Br switch places.

If it is three moles of NaOH i.e 3 NaOH

The number of atoms in each mole = 3 moles atoms

so total moles of atom = 9 moles of atom

in each mole of atoms = 6.023 X 10^23 atoms

so total atoms in three moles of NaOH = 9 X 6.023 X 10^23 atoms

= 5.4207 X 10^24 atoms

Answer: pOH = 3.13

Ba(OH)2 is a very basic substance. The general formula for pOH is - log(OH)

Barium Hydroxide produces 2 moles of OH for every mole of Ba(OH)2 present in the solution.

0.00037 M = 3.7 * 10^-4 Ba(OH)2 will produce 2 *0.00037 M of OH-

OH- = 2* 0.00037 = 0.00074

pOH = - log(0.00074) = 3.13

Answer:

3.13

Explanation:

Hi!

The correct options would be:

1. Cathode - reduction

The cathode is the negatively charged electrode, and so has an excess of electrons. Cations (positively charged ions) are attracted to the cathode, and gain electrons to acquire a neutral charge. The process in which a gain of electron occurs is called reduction.

2. Anode - oxidation

The opposite occurs at the anode which is positively charged and attracts negatively charged ions, anions. These anions lose their electrons at the anode to acquire a neutral charge, and the process involving loss of electrons is known as oxidation.

3. Salt Bridge - ion transport

Salt bridge is a physical connection between the the anodic and cathodic half cells in an electrochemical cell and is a pathway that facilitates the flow of ions back and forth these half cells. Salt bridge is involved in maintaining a neutral condition in the electrochemical cells, and its absence would result in the accumulation of positive charge in the anodic cell, and negative charge in the cathodic cell.

4. Wire - electron transport

Wires have a universal role of being a pathway for the transport of electrons in circuit. This role is also the same in the wires involved in an electrochemical cells where they are used to transport electrons from the anodic half cell, and this electron transport results in the generation of electricity in the internal circuit of the electrochemical cell.

Hope this helps!

C. Nonmetals are usually gases at room temperature. Only a few nonmetals are solid, and one (Bromine) is liquid.

Nonmetals are elements that are generally poor conductors of heat and electricity, so (A), on your far left of the periodic table

They are also typically gases or brittle solids at room temperature. Nonmetals are found on the right side of the periodic table, with the exception of hydrogen, which is found in the top left corner.

Nonmetals are an important part of the periodic table, and they play a role in many different compounds and materials. For example, oxygen is a nonmetal that is essential for life. Carbon is a nonmetal that is used to make plastics and other materials.

Find out more on non metals here: https://brainly.com/question/18310417

#SPJ6

Answer:

292 mL

Step-by-step explanation:

The pressure is constant.

The only variables are volume and temperature, so we can use Charles’ Law.

V₁/T₁ = V₂/T₂     Multiply each side by T₂

V₂ = V₁ × T₂/T₁

V₁ = 250 mL; T₁ = 300 K  

V₂ = ?;           T₂ =  350 K

V₂ = 250 × 350/300

V₂ = 292 mL

 Over 344.76 K  the  forward reaction will be spontaneous

 calculation

ΔG  = ΔH° -TΔs

if ΔG =0

therefore  0 =ΔH°-TΔs

ΔH°   = TΔs

divide  both side  by   Δs

T = ΔH°/Δs

convert 34.2 kj into j

 that  is 1 kj = 1000 j

        34.2 kj =? j

by cross  multiplication

=[34.2 kj x 1000j / 1 kj] = 34200 j

T  is therefore = 34200 j÷99.2 j/k =344.76 k

if  T is greater than  344.76 k  the forward reaction  will be spontaneous

The calculation of temperature is done as follows:

T = ΔH°/ΔS°

= 34.2 kJ/mol / 99.2 × 10⁻³ kJ/molK

= 345 K

Since, ΔS° and ΔH° comes out to be positive for the given reaction. Hence, the given reaction is spontaneous at higher temperature and non spontaneous at lower temperature. Thus, it can be said that above 345 K, the given reaction will become spontaneous.

The alkali metals takes column 1 A of the periodic table.some of them are hydrogen, potassium,lithium etc. The elements gets into their ionic +1 form because they easily lose their one electron in the outermost shell.This one electron is the outermost layer of electrons is responsible for the various properties of alkali metals.

Alkali metals all form cations with a +1 charge upon ionization due to the easy loss of their single valence electron. This is due to their large atomic radii and low first ionization energies.

The elements in the first column of the periodic table, known as alkali metals, include lithium, sodium, potassium, rubidium, cesium, and francium. These elements are characterized by having the largest atomic radii in their respective periods and the lowest first ionization energies, which makes it easy for them to lose their single valence electron. When ionized, alkali metals all form stable cations with a +1 charge.

The periodic table can thus be used as a tool to predict the charge of ions based on an element's location. For instance, all alkali metal ions have a +1 charge, and the convention is to write the number and then the sign, like Li+ or Na+, illustrating that each alkali metal cation has one positive charge.

Answer: The conductivity of the solution is very low or near zero

Explanation:

Covalent compounds do not have free electrons and do not dissociate into ions. Ions are the charge carriers in solution and are responsible for the conductivity of electrolyte solutions. Non-electrolytes do not dissociate into ions hence they do not conduct electricity in solution. The conductivity is very low due to the absence of ions making the solution unable to conduct electricity.

The kinetic energy per mol of gaseous water molecules at 25°C is approximately 3.72 KJ/mol.

The kinetic energy of gaseous molecules can indeed be calculated using the equation KE = (3/2) * k * T, where KE represents kinetic energy, k is the Boltzmann constant (1.381 x 10^-23 J/K), and T is the temperature in Kelvin. To perform this calculation for gaseous water molecules at 25°C, you correctly converted the temperature from Celsius to Kelvin (25°C = 298.15 K).

So, KE = (3/2) * (1.381 x 10^-23 J/K) * (298.15 K) = 6.18 x 10^-21 J per molecule.

To determine the kinetic energy per mole of gaseous water molecules, you can indeed multiply this value by Avogadro's number (6.022 x 10^23 molecules/mol):

(6.18 x 10^-21 J/molecule) * (6.022 x 10^23 molecules/mol) ≈ 3.72 kJ/mol.

https://brainly.com/question/26472013

#SPJ12

The kinetic energy of 1.00 mole of gaseous water molecules at room temperature can be calculated using the equation KE = (3/2)RT, assuming the molecules are ideal. The temperature needs to be converted to Kelvin before plugging it into the equation.

The kinetic energy of 1.00 mole of gaseous water molecules at room temperature can be calculated using the equation for translational kinetic energy. We can obtain the average kinetic energy of a molecule by dividing out the number of molecules and multiplying by 3/2. Assuming the gaseous water molecules are ideal, we can use the equation KE = (3/2)RT to calculate the kinetic energy, where R is the gas constant and T is the temperature in Kelvin.

Using the given temperature of 25.0ºC, we need to convert it to Kelvin by adding 273.15 to the Celsius temperature. So, 25.0ºC = 25.0 + 273.15 = 298.15 K. Assuming R = 8.314 J/mol·K, we can calculate the kinetic energy as follows:

KE = (3/2)(8.314 J/mol·K)(298.15 K) = 18659.6 J/mol

https://brainly.com/question/26472013

#SPJ12

the answer is ( . a rocket in space )

Answer:

The correct option is B

Explanation:

The mass of an object is the amount of substances/molecules present in that object. The mass of an object remains the same anywhere regardless of gravity. In space, where there is no gravity, the mass of a rocket remains the same but the weight will be different because of zero gravity which means there will be no force of gravity pulling the rocket towards itself.

Hence, weight can be calculated as

Mass of an object (in kg) × gravitional field strength (in N/kg)

From the above formula, it can be deduced that weight is dependent on mass and gravity but mass is not (when you make mass the subject of the formula).

B. 50 km

Seeing as the truck would travel approximately 100 kilometers in an hour, or 60 minutes, it would travel half that distance in half the time--50 kilometers in a half hour, or 30 minutes.

Answer:B

Explanation:

Speed= distance/time

Distance= speed× time

Speed= 100km/hr

Time= 30 mins or 0.5 hours

Therefore: distance= 100×0.5= 50Km

Note:60 minutes make one hour!

The mass of protons and neutrons are both 1 amu (atomic mass unit). The mass of the electron is 0.00054. Therefore, when determining the isotopes when given mass, you only focus on the neutrons as they are the subatomic particles that are significantly affecting the atomic mass.

Final answer:

The mass of an electron is about 1836 times less than that of a proton or a neutron, meaning protons and neutrons contribute the most to an atom's mass. Electrons are significantly lighter and do not significantly contribute to the atomic mass.

Explanation:

When comparing the mass of an electron to that of protons and neutrons, we observe that electrons are significantly lighter in mass. A proton has a mass of approximately 1.0073 atomic mass units (amu), while a neutron is a bit heavier with a mass of about 1.0087 amu. In contrast, an electron has a mass of roughly 0.00055 amu. This means that the mass of a proton or a neutron is about 1836 times greater than that of an electron. Consequently, protons and neutrons account for nearly all of an atom's mass, with the mass of electrons being almost negligible in comparison.

Electrons and protons also have electrical charges that are equal in magnitude but opposite in sign, with electrons having a charge of -1 and protons a charge of +1. Neutrons, on the other hand, are electrically neutral and do not bear any charge. Despite their small mass, electrons play a critical role in defining the chemical properties of atoms due to their negative charge and involvement in chemical bonds.

Answer:coal and oil

Explanation:

  The reaction CO₂(g)  → C(s) +O₂(g)  is  a decomposition  reaction is true

Explanation

 A Decomposition reaction is a reaction in which involve breaking down  a compound into   two or more  simpler  substances.

 The reaction above is a decomposition reaction since CO₂    molecule is broken down  into C (an  element) and O₂  (a  molecule).

Answer:

True

Explanation:

ILL FREAKING DIE FROM LOVE lol

That would e awesome

The answer cvould be syrup

Syrup, Honey, Milk, and Soda.

Answer is: D.silicon and phosphorus.

When the electronegativity difference is greater, the bond polarity is increasing..  

Electronegativity (χ) is a property that describes the tendency of an atom to attract a shared pair of electrons.  

Atoms with higher electronegativity attracts more electrons towards it, electrons are closer to that atom.  

A) Δχ(Bi-S) = 2.5 - 2.0 = 0.5; polar covalent.

B) Δχ(C-O) = 3.5 - 2.5 = 1.0; polar covalent.

C) Δχ(N-O) = 3.5 - 3 = 0.5; polar covalent.

D) Δχ(Si-P) = 2.2 - 1.9= 0.3; nonpolar covalent.

he got shot while shielding a child

Before I answer, I wanna say that my school uses that EXACT same program! Is it called USATestPrep? Tell me if so!

ANYWAY, the answers are:

DNA:

Gene:

Protein:

Chromosome:

Answer:

Economics is a social science that focuses on the study of human activity and behavior and its relationship with the administration of the processes of extraction, production, exchange, distribution and consumption of goods and services.

Explanation:

Economics is a social science that studies the processes of extraction, production, exchange, distribution and consumption of goods and services. In other words, economics is a social science that studies how to manage the resources available to meet human needs, also studying the behavior and actions of human beings, their interaction with certain events and the effect they produce on their environment.

In this way the economy tells us how societies use scarce resources to produce goods with value, and how they make the distribution of wealth among individuals.

In summary, economics is a social science that focuses on the study of human activity and behavior and its relationship with the administration of the processes of extraction, production, exchange, distribution and consumption of goods and services.

Economics is a social science concerned with decision-making in the context of scarcity, analyzing individual to societal level choices regarding resource allocation.

Economics is a social science that focuses on how humans make decisions in the face of scarcity. It explores various types of decisions, including individual, family, business, and societal choices, and the motivating factors behind these decisions. Due to the scarcity of goods, services, and resources like labor, tools, land, and raw materials, economics scrutinizes how these limited resources are allocated to meet the infinite wants of people. Moreover, time is considered an ultimate scarce resource, since we all have a finite amount of it to use each day.

Economics can be broadly categorized into two main areas: microeconomics, which studies the behavior and decisions of individual units such as households and firms, and macroeconomics, which examines the economic activity of an entire nation or the global economy. As a discipline, it uses a scientific approach to analyze and understand the financial and resource allocation decisions and their impacts on society.

Hm, this could be more than one option, but gaining electrons makes a negative charge, so

If atoms of a halogen nonmetal (Group 17) gains one electron, the atoms the have "a negative one charge".

Answer:

Atoms of a halogen nonmetal gain one electron, the atom has a -1 charge.

Explanation:

The halogen non-metals of Group 17 have 7 valence electrons in their valence shell.

For an element to complete its octet and reach the stable configuration, 8 electrons are required. On gaining an electron the must be an impartment of a negative charge onto the element.

For group 17 elements to complete the octet they need to withdraw one atom. So the charge must be 1.

Since they are accepting the electron, they impart a negative charge.

So, group 17 halogen metals on gaining 1 electron have a -1 charge.

For more information, refer the link:

https://brainly.com/question/11156152?referrer=searchResults