Which of the following sequences of elements would all have four valence electrons?

A.) B, Si, As, Te

B.) C, Si, Ge, Sn

C.) O, S, Se, Te

D.) Ga, Ge, As, Se

Heat packs are used to relax muscles. This reaction is an example of exothermic reaction.

Exothermic reaction is defined as a reaction that is chemical in nature and is characterized by the release of energy in the form of heat and light.

It can also be defined as a thermodynamic process or reaction that releases energy from system to its surroundings.

Endothermic reaction is defined as the chemical reaction in which the reactants absorbs heat energy from the surroundings to form product.  

Endothermic reaction can also be defined as a reaction in which the system absorbs energy from its surroundings in the form of heat.

Being endothermic enables us to live in cooler environments and regulate our body temperatures in order to fight infection.

Thus, heat packs are used to relax muscles. This reaction is an example of exothermic reaction.

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Answer:

2H+0 =H2O

Explanation:

May this help you

Answer:

Yes

Explanation:

Answer:

b

Explanation:

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The formula equation is more meaningful than a word equation because the word equation only defines what the reactants and products are, whereas the formula equation defines which and how much of each element is present in the chemicals and also give some indication as to their structure.

Answer:

The formula equation is more meaningful than a word equation because the word equation only defines what the reactants and products are, whereas the formula equation defines which and how much of each element is present in the chemicals and also give some indication as to their structure

Explanation:

The formula equation is more meaningful than a word equation because the word equation only defines what the reactants and products are, whereas the formula equation defines which and how much of each element is present in the chemicals and also give some indication as to their structure

There are 1.16x10²² sulfide ions (S²⁻) in 15 dg of sodium sulfide (Na₂S).

The equation for sodium sulfide is the following:

Na₂S → 2Na⁺ + S²⁻  (1)

So from equation (1), we can see that in 1 mol of sodium sulfide we have 1 mol of sulfide ions and 2 moles of sodium ions.

First, let's find the number of moles of Na₂S

[tex] n_{Na_{2}S} = \frac{m_{Na_{2}S}}{M_{Na_{2}S}} [/tex] (2)

Where:

[tex]m_{Na_{2}S}[/tex]: is the mass of Na₂S = 15 dg = 1.5 g    

[tex]M_{Na_{2}S}[/tex]: is the molar mass of Na₂S = 78.0452 g/mol

The number of moles of Na₂S is (eq 2):

[tex] n_{Na_{2}S} = \frac{1.5 g}{78.0452 g/mol} = 0.0192 \:mol [/tex]

We can find the number of ions of S²⁻ with Avogadro's number, knowing that the number of moles of Na₂S is equal to the number of moles of S²⁻ (eq 1).  

[tex] ions_{S^{2-}} = \frac{6.022 \cdot 10^{23} \:ions}{1\:mol}*0.0192 \:mol = 1.16 \cdot 10^{22} \:ions [/tex]

Therefore, there are 1.16x10²² sulfide ions in 15 dg of sodium sulfide.

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I hope it helps you!

Answer:

pyruvic acid changes to alcohol and carbon dioxide.

Explanation:

In lactic acid fermentation, pyruvic acid from glycolysis changes to lactic acid. This type of fermentation is carried out by the bacteria in yogurt, and by your own muscle cells.

I HOPE THIS HELPS!!!!!

Alcohol and carbon dioxide are produced when pyruvic acid is fermented. The chemical process in which molecules break down is called as fermentation.

Fermentation is an anaerobic chemical process that breaks down molecules like glucose. Pyruvic acid undergoes fermentation to produced lactic acid.

More specifically, fermentation is the foaming that happens during the creation of wine and beer, a procedure that has been around for at least 10,000 years.

Pyruvic acid produced during glycolysis transforms into lactic acid during lactic acid fermentation. Alcohol and carbon dioxide are produced when pyruvic acid is fermented.

Thus, the pyruvic acid when change into lactic acid fermentation obtained alcohol and carbon dioxide.

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Answer:

Explanation:

Carbon monoxide →  Prevents oxygen from being transported in the body

Nitrogen oxides → Can cause asthma

Particulate matter → Irritates lungs, dizziness, seizures, or death

Sulfur oxides → Inflammation and irritation of the respiratory system

I hope this helps!

Sulfuric acid reacts violently with alcohol and water to release heat. It reacts with most metals, particularly when diluted with water, to form flammable hydrogen gas, which may create an explosion hazard. ... Hazardous decomposition products are as follows: sulfur dioxide, sulfur trioxide, and sulfuric acid fumes.

it acts violently with water or alcohol to release some heat, it does react to most metals, mostly when diluted with water to form flammable hydrogen gases, which may create an explosion hazard.

(i tried to make the g00gle answer less complicated) :)

Answer:

fussion

your welcome

Refer to the attachment

Light waves are part of the electromagnetic spectrum. The frequency of light therefore is 1.5 * 10^15 Hz.

Light is an electromagnetic wave and we know that the speed of light is a constant which is 3 * 10^8 m/s.

Knowing this; v = λ * f

λ = wavelength

f= frequency of light

v = seed of light

f = v/λ

f =  3 * 10^8 m/s/2.0 x 10-7 m

f = 1.5 * 10^15 Hz

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Answer:

A : 1,923 m/s

Explanation:

= 500/0.26

= 1,923

Answer:

18 electrons

Explanation:

when l=1, this tell you that it is "p sub shell"

Answer

85

Explanation:

Astatine has an atomic number of 85.

This means it has 85 positively charged protons.

If it is neutral, it must have the same number of negatively  charged electrons, or 85

Answer:

that donate H+ ion.

Explanation:

hope this helps :)

Answer:

cholesterol(lipid)

Explanation:

Ribosomes are called PROTEIN FACTORY

Ribosomes are involved in protein synthesis

Any metabolite or substance protein in nature can be synthesized on ribosomes

Since they are protein in nature hence can be synthesized on ribosome.

WRONG OPTIONS:

CHOLESTEROL IS LIPID IN NATURE

LIPIDS ARE NOT proteins and cannot be SYNTHESIZED ON RIBOSOME

LIVER DOES THIS FUNTION OF CHLESTEROL SYNTHESIS.

Answer:

In a movable pulley system, where does the other effort come from? is carried by this end of the rope. This means that the structure (ceiling) does half the effort.

Explanation:

We can use the formula M₁V₁ = M₂V₂ the total volume of water that will yield 0.800 M HCl. We can then subtract that from the initial volume to get how much water needs to be added.

Since M₁V₁ = M₂V₂    (starting mole× starting volume = end mole × end volume)

⇒  (5 mol)(20 mL) = (0.80 mol) V₂

         100 mol/mL = 0.8 mol × V₂

⇒                      V₂ = 100 mol/mL ÷ 0.8 mol

                             = 125 m

Since we began with 20.0 mL of water,

water needed to add = 125 mL - 20 mL = 105 mL

Answer:

Centríolo. Los Centríolos son orgánulos tubulares (en pares de dos en dos) que se encuentran en el citoplasma de las células animales, cerca de la membrana nuclear. Los centriolos tienen la función de organizar los microtúbulos, que son el sistema esquelético de la célula.

Explanation:

Espero te ayude

Answer:

Fiber-rich, complex carbs

Complex carbs with fiber take much longer to digest than simple carbs. This helps to maintain stable blood sugar levels because sugar enters the bloodstream gradually . Complex carbohydrates provide sustained energy and help you feel fuller for longer because they are digested more slowly.

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Write a Balanced Equation for the decomposition

CaCO₃     →     CaO    +    CO₂

Find Moles of CO₂ Produced

Since the mole ratio of  CaCO₃  to CO₂ is 1 to 1,

the moles of CaCO₃ = moles of CO₂

moles of CaCO₃   = mass ÷ molar mass

                             = 300 g ÷ 100.087 g/mol

                             = 2.997 moles

∴ moles of CO₂ = 2.997 moles

Determine Mass of CO₂

Mass = moles × molar mass

         = 2.997 mol × 44.01 g/mol

         = 131.9 g

Standardization is the process of titrating a solution that is prepared from: a carefully measured solid mass to accurately find the concentration of titrant.

Titration is also known as volumetric analysis (titrimetry) and it can be defined as a chemical process in which a solution of known concentration (titrant) is carefully and slowly added to another solution of unknown concentration, so as to determine the concentration or quantity of the analyte.

Similarly, a process referred to as standardization is used to titrate a solution that is prepared from a carefully measured solid mass to accurately find the concentration of titrant.

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Answer:

Chromatography involves solvent separation on a solid medium. Distillation takes advantage of differences in boiling points. Evaporation removes a liquid from a solution to leave a solid material. Filtration separates solids of different sizes.

Explanation:

give brainliest

Answer:B

Explanation:

A positively charged object attracts an uncharged object.

A positively charged object attracts an uncharged object statement is in correct in the table. Hence option B is correct.

Charge are defined as a subatomic particle's ability to experience force when exposed to an electric and magnetic field. The value that the atom reaches after removing or gaining electrons is known as charge. Only ions that comply with the octat rule are stable. Atoms or groups of atoms with an electric charge are referred to as ions. Cations are positive-charged ion particles. Anions are ion types that have a net negative charge.

A charged object will cause an opposing charge to be applied to an uncharged object when it is brought close to the charged one. These two things are drawn to one another because opposing charges attract one another. Other charged items are drawn to a charged object whereas uncharged objects are repelled by it.

Thus, a positively charged object attracts an uncharged object statement is in correct in the table. Hence option B is correct.

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Answer:

i believe it is c

evaporation

Explanation:

Hope it's the correct one if not very sorry.