Identify the group number and generic outer electron configuration for a neutral main‑group element with the following two Lewis dot symbols.

X with 1 dot on the top, bottom and right

X with 1 dot on all sides

Half-life of C-14 is 5730 years

The age of the bone is the time taken to decay carbon -14 from a mass of 80 g to 0.3125 g. The decay time is 46209 years. That is the age of the bone.

Carbon -14 isotope is radioactive and undergoes nuclear decay by the emission of charged particles. The age of a fossil sample which contains carbon -14 can be determined using the time of decay.

Half life of C-14 = 5730 years

decay constant k = 0.693 / 5730 = 0.00012 yr⁻¹

Initial amount of C-14 = 80 g

final amount = 0.3125 g

Then the time taken to decay 80 g to 0.3125 g is t = 1/k ln (80/0.312)

t = ln (80/0.312) / (0.00012 yr⁻¹)

 = 46209 years.

Therefore, the age of the bone is 46209 years.

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Answer:

The label may instruct you to shake a liquid medicine before using so that the active ingredients are evenly distributed throughout it.

Explanation:

Answer:

maybe because if somehow the liquids get separated then shaking them up would mix them back to how they are suppose to be originally.

Explanation:

Answer:

s orbital

Explanation:

it has the lowest energy because

Paulis law state that orbitals with lower energy must be fill first before that of higher energy

and the s orbital is filled first

Answer:

K = [N2] [Cl2]³ / [NCl3]²

Explanation:

The equilibrium expression, K, of a reaction:

aA + bB ⇄ cC + dD

Is defined as the ratio between the multiplication of concentrations of products powered to its reaction coefficient and the multiplication of concentrations of reactants powered to its reaction coefficient as follows:

K = [C]^c[D]^d / [A]^a[B]^b

Now, for the reaciton:

2NCl3 ⇄ N2(g) + 3Cl2(g)

K is:

K = [N2] [Cl2]³ / [NCl3]²

Answer:

11.92 Liters O₂(g) at STP

Explanation:

For most stoichiometry problems, if one will convert all given data into moles, solve by rxn ratios, then finish by converting to needed dimensions to complete problem.

2Pb(NO₃)₂ => 2PbO + 4NO₂ + O₂

Given 237.5 grams PbO formed in reaction = 237.5 g/223.2 g/mole = 1.064 mole PbO

From equation ratios, moles O₂ formed = 1/2(moles PbO) = 1/2(1.064 moles O₂) = 0.532 mole O₂

0.532 mole O₂ = 0.532 mole x 22.4  liters/mole at STP = 11.91756272 liters (calculator answer) ≅ 11.92 liters O₂ at STP (4 sig.figs. based on given 237.5g PbO)

Answer:

A). half, higher

Explanation:

The Formal charge is elaborated as the 'allocated charge to a molecules' atom' on the basis of the assumption that the electrons present in the chemical bond are equally split among the atoms. It is estimated by 'halving the no. of bonding electrons that encircle the atom.

While Oxidation number is characterized as the 'hypothetical charge of an atom that is present within a molecule.' It is also defined as 'the actual number of lost or gained electrons or the rate at which the electrons are gained or lost by an atom to develop a chemical bond along with the other atom.' It is calculated by allocating or sharing the electrons having the higher electronegativity belonging to a specific bond with the other. Thus, option A is the correct answer.

Answer: cats r alliens because they r kind of like ufos they would usually wonder around rather u know it or not when they spy on us it could b with us sleep cooking anything so they r like aliens

Explanation:

Answer:

5,000 g

b.)catalyst

The catalyst makes it possible for the reaction to take place by another path that makes possible reaction at a lower energy.

activation

activation energy

Explanation:

Formulae for molality = number of moles of solute/mass of solvent in kilograms

Number of moles of solute= 11.75g/236 g/mol = 0.0498 moles

0.01 = 0.0498/x

x= 0.0498/0.01

x= 5 Kg or 5000 g

A catalyst refers to any substance that alters the rate of reaction but remains unaffected at the end of the reaction. The catalyst lowers the activation energy of a reaction.

For a chemical reaction to occur, the substances participating in that reaction must possess energy which is greater than the activation energy of the reaction. The activation energy is a sort of energy barrier between reactants and products which must be surmounted before a reaction can take place.

When the temperature of a reaction system is raised, the molecules move faster and the number of effective collisions in the system increases. However, raising the temperature does not raise the activation energy of the system.

Answer:

It is based on testable and replicable evidence.

crystalline solids are the type of solid which have long term arrangement of particle

they have sharp melting and boiling point

Answer:

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Answer:

in most of the endothermic reactions the atoms gains electrons from one to another. since the atom gains electrons there is a electron repulsive force between the host and the guest electron . As stability is inversely proportional to electron repulsive force the atom gains energy to attain stability .

The endothermic reaction mostly come under electron affinity

Explanation:

hope this helps you

if  I am wrong just correct me

Answer:

(b) A and C belongs to same group.

(c) D is a non metal.

Explanation:

The Electronic Configuration of E is

[tex]1s {}^{2} 2s {}^{2}2p {}^{6} 3s {}^{2} 3p {}^{6} 4s {}^{2} [/tex]

Water molecules pull the sodium and chloride ions apart, breaking the ionic bond that held them together.

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Answer:

D- Release of dust during volcanic eruption

Explanation:

During major explosive eruptions huge amounts of volcanic gas, aerosol droplets, and ash are injected into the stratosphere. Injected ash falls rapidly from the stratosphere -- most of it is removed within several days to weeks -- and has little impact on climate change. But volcanic gases like sulfur dioxide can cause global cooling, while volcanic carbon dioxide, a greenhouse gas, has the potential to promote global warming.

answer:

a - decrease in the suns energy.

explanation:

although the other options do discuss climate, temperature, etc., the sun DIRECTLY influences the earth's climate and would most likely affect it on a larger scale. for example, warm and cold ocean currents would affect the temperature of the ocean and could touch bay cities or islands, but they would not dictate the overall climate of the earth :)

♡ hopefully my reply helped you come to an answer~ please keep in mind that my response is purely that... MY response! i still have lots to learn, so please correct/educate me if you have found otherwise ♡

The thickness of one button will be 2mm

* N.B: We convert the height of the 12 buttons to same unit (mm)

Then, 2cm = 2 × 10 = 20mm

20mm + 4mm = 24mm

24/12 = 2mm thick

Hence, one button is 2mm thick.

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Answer:

Grey school buses would likely get in more accidents because other drivers are expecting a yellow bus to make frequent stops and the lights and stop sign are noticeable on a brighter color.

Explanation:

yellow buses are easier to see in fog than a grey bus

Answer:

53.9541 pound force...

Answer:

The answer is in the explanation.

Explanation:

The KHP is an acid used as standard in titrations to find concentration of bases as NaOH.

The reaction that explain this use is:

KHP + NaOH → KNaP + H2O

where 1 mole of KHP reacts per mole of NaOH

That means, at equivalence point of a titration in which titrant is NaOH, the moles of KHP = Moles of NaOH added

With the moles of KHP = Moles of NaOH and the volume used by titrant we can find the molar concentration of NaOH.

The moles of KHP are obtained from the volume and the concentration as follows:

Volume(L)*Concentration (Molarity,M) = moles of KHP

If the concentration is more or less than 0.100M, the moles will be higher or lower. For that reason, we need to know the concentration of KHP but is not necessary to be 0.100M.

Answer:

ionic

Explanation:

I'll put the rest if the answers in comments

Answer:

1. Metallic bonds are responsible for many properties of metals, such as conductivity. Why is this possible?

*The bonds can shift because valence electrons are held loosely and move freely.*

2. Between which types of elements do ionic bonds occur, and how do electrons act within the bond?

*metals and nonmetals, electrons transferred*

3. Which kind of bond would occur between sodium (Na, Group IA) and chlorine (Cl, Group VIIA)?

*ionic*

4. Which type of bond and how many bonds would occur as carbon dioxide (CO2) is formed from carbon in Group IVA and oxygen in Group VIA?

*four covalent bonds*

5. How many covalent bonds is nitrogen (Group 5A) likely to form?

*three*

These are all the answers to the Bonds Quick Check.

Answer:

c2h4 (etthane........

bexcuse it has 6 bond of hydrogen

C₂H₄ molecules contains six bonding electrons. Therefore, option A is correct.

Chemical bonding is the process through which two or more atoms, molecules, or ions establish a chemical link to create a chemical compound. The atoms in the resultant molecule are held together by these chemical bonds.

Chemical bonds have three basic characteristics that must be taken into account: their strength, length, and polarity. The distribution of electrical charge among the atoms connected by a bond determines its polarity.

C₂H₄ molecules has six bonding electrons. This molecule is called as Ethylene. When bonding is done between two atoms, each atom shares a pair of electrons with each other.

Hence, for every one bond, two electrons are shared between two atoms

Thus, option A is correct.

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Answer:

The answer is "Option i"

Explanation:

In this question, only option (i) is correct, and others were wrong which can be defined as follows:

In option (ii):

[tex]Na^+\ (aq)+Cl^- \ (aq) +Ag^+ \ (aq)+NO_3^- \ (aq) \to AgCl\ (s)+Na^+ \ (aq)+NO_3^-\ (aq) \\\\[/tex]

It is the complete ionic equation.

In option (iii):

[tex]CH_3OH\ (g)+O_2\ (g) \to CO_2\ (g)+H_2O\ (g)[/tex]

It is the combustion reaction but a not balanced equation.

In option (iv):

[tex]2H_2O\ (l) \to 2H_2\ (g)+O_2\ (g)[/tex]

It is the  decomposition equation.

In option (v):

[tex]H^+\ (aq) +OH^-\ (aq)\to H_2O\ (l)[/tex]

It is the complete ionic equation.

Answer:

the uses of exothermic reactions are:

1) lighting of stove

2) self heating cans

3) hand warmers

4) in some case exothermic process can be used to cook food such as rice  (by adding calcium oxide to water heat is evolved and it helps to cook food )

Explanation:

hope this helps you pls mark me as brainilst

Answer:

Explanation:

48000 minutes [ 1 hour  / 60 min ] 1 day / 24 hours ] [365 days / year]

48000 * [ 1/(60 * 24 * 365)]

48000 * [1 / 525600]

There are 0.0930954years in 48000 minutes

Answer:

In fact, in many neurons three sodium ions are transported for every potassium ion; sometimes the ratio is three sodium ions for every two potassium ions, and in a few neurons it is two sodium ions for one potassium ion.

cubic unit cell is the smallest repeated unit which have all angles equal to 90 and all have edge lengths equal

It is the type of the Unit cell which is having all angles equal to 90 and all sides equal to each other

it's is a unit cell with cubic structure

Answer:

The Noble Gases have eight valence electrons, which fill their outer energy level. This is the most stable arrangement of electrons, so noble gases rarely react with other elements and form compounds.

Hope this helps!

Answer:

chemistry - the science that studies the properties of substances and natural fenomens .

...........

Answer:

The Basic definition of Chemistry is:-

Chemistry is the scientific study of the properties and behavior of matter. It is the natural science that covers the elements that make up matter to the compounds that is composed of atoms, molecules and ions.

Teniendo en cuenta que la molaridad es el número de moles de soluto que están disueltos en un determinado volumen, la molaridad de la disolución de HNO₃ es 14.67 [tex]\frac{mol}{L}[/tex].

El porcentaje en masa o en peso de una disolución es el número de gramos de soluto que hay por cada 100 gramos de disolución.

Entonces una pureza de 65% indica que hay 70 g de HNO₃ puro por cada 100 g de HNO₃ impuro.

Por otro lado, la densidad es la relación entre el peso o masa de una sustancia y el volumen que ocupa esa misma sustancia.

Entonces, si la disolución de HNO₃ tiene una densidad de 1.32 g/mL (equivalente a 1320 g/L), donde la cantidad de masa es impura, se puede obtener la cantidad de masa de HNO₃ presente 1 L de la solución mediante el siguiente cálculo:

[tex]\frac{1320 g HNO_{3} impuro}{1 L}x \frac{70 g HNO_{3}puro}{100 g HNO_{3}impuro}= 924 \frac{g HNO_{3}puro}{L}[/tex]

Finalmente, la masa molar de HNO₃, es decir la masa presente en un mol de la sustancia, es 63 [tex]\frac{g}{mol}[/tex].

Entonces, teniendo en cuenta que la molaridad es el número de moles de soluto que están disueltos en un determinado volumen, es posible determinar la molaridad como:

[tex]\frac{924 g HNO_{3}puro}{L}* \frac{1 mol}{63 g}= 14.67 \frac{mol}{L}[/tex]

En resumen, la molaridad de la disolución es 14.67 [tex]\frac{mol}{L}[/tex]

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