Which of the following shows a valid combustion reaction?

2Al + 2O2 → 2AlO + O2
C2H4 + 3O2 → 2CO2 + 2H2O
2CH4 + O2 → 2CO + 4H2
Ca + O2 → CaOH

Answer:

[tex] \huge{5.77 \times {10}^{ - 5} m}[/tex]

Explanation:

The wavelength of a wave can be found by using the formula

[tex]\lambda = \frac{c}{f} \\[/tex]

where

c is the speed of the wave

f is the frequency

From the question we have

[tex] \lambda = \frac{3 \times {10}^{8} }{5.2 \times {10}^{ 12} } \\ \\ \\ \\ \large{ = 5.77 \times {10}^{ - 5} m}[/tex]

Hope this helps you

Answer:

ZnBr2

Explanation:

KNO3 + LiOH -------> no reaction

This is because KNO3 and LiOH completely ionize.in water and form neutral solutions.Since both are neutral no reaction occurs

NH4Cl + LiOH -----> NH3 (aq) + H2O (l) + LiCl(aq)

None of the above products are precipitates

Ca(C2H3O2)2 + 2LiOH -----> Ca(OH)2 (aq) + 2LiC2H3O2 (aq)

ZnBr2 + 2LiOH -----> Zn(OH)2 (s) + LiBr2 ( aq)

Zn(OH)2 thus formed is a white precipitate

However when excess LiOH is added Zn(OH)2 precipitate will dissolve to give a clear solution of Li2ZnO2 .

You can remember this by the fact that Na,K,Rb,Cs,Ca,Sr,Ba hydroxides are soluble in water and all other hydroxide are precipitated in water

Zn(OH)2 (s) + 2 LiOH ------> Li2ZnO2(aq) + 2 H2O ( l)

The only compound that will form a precipitate with LiOH would be ZnBr2

These are double displacement reactions in which precipitates are produced. Precipitates are insoluble solids formed from the combination of ions in aqueous solutions.

In this case, a reaction between LiOH and ZnBr2 would be as follows;

2LiOH + ZnBr2 ----------> 2LiBr + Zn(OH)2 (s)

Zn(OH)2 is an insoluble salt and will precipitate out in the solution.

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Answer:

0.1× Avogadro's numbers

10×10^22

Explanation:

convert given mass to moles

then multiply by Avogadro's number

Answer:

20c answer is 20c hiuyffddffffy

Answer:

17000

J

(2 significant figures

Answer:

1 marcomolecules are:- A macromolecule is a very large molecule, such as a protein. They are composed of thousands of covalently bonded atoms. Many macromolecules are polymers of smaller molecules called monomers.

2 polymers are:- a natural or artificial chemical compound consisting of large molecules

Explanation:

hope it helps you

pH = pKa + log [NaAc]/[HAc]

4.140 = 4.74 + log x

log x = -0.60

x = [NaAc]/[HAc] = 0.25

moles HAc = 1.50 L x 0.287 mol/L = 0.431 moles

moles NaAc = 0.25 x 0.431 = 0.1078 moles NaAc

grams NaAc = 0.108 x 80 g/mole = 8.64 grams

Answer:could u expand on the question

Explanation:

Answer:

specific heat capacity of the unknown is 629.66 J/kg C

Explanation:

As we know that gold is heated to 72.3 degree C and mixed with water at 24.8 degree C

Now the final temperature of the mixture is 26 degree C

here we can say that heat given by the gold = heat absorbed by the water

So we will have

Q_{in} = Q_{out}Q

in

=Q

out

2.62 s (72.3 - 24.8) = 15.6 (4186) (26 - 24.8)2.62s(72.3−24.8)=15.6(4186)(26−24.8)

so we will have

s = 629.66 J/kg Cs=629.66J/kgC

so specific heat capacity of the unknown is 629.66 J/kg C

Answer:

Freeze wedging is caused by the repeated freeze-thaw. Frost wedging occurs as the result of 9% expansion of water when it is converted to ice. Cracks filled with water are forced further apart when it freezes.

Answer:

one end is the north pole and the other is the south pole.

Explanation:

a north pole will attract a south pole; the magnets pull on each other. But the two north poles will push each other away. ... A compass is a tiny magnet balanced on a point so it can turn freely.

Answer: Atoms are made of dust because God made us with dust.

Explanation:

Answer:yes

Explanation:

this is because the distance doesnt matter

Answer:

Group 2A (or IIA) of the periodic table are the alkaline earth metals:  beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra).  They are harder and less reactive than the alkali metals of Group 1A.  The name comes from the fact that the oxides of these metals produced basic solutions when dissolved in water, and they remained solids at the temperatures available to the ancient alchemists.  Like the Group 1A elements, the alkaline earth metals are too reactive to be found in nature in their elemental form.

The alkaline earth metals have two valence electrons in their highest-energy orbitals (ns2). They are smaller than the alkali metals of the same period, and therefore have higher ionization energies.  In most cases, the alkaline earth metals are ionized to form a 2+ charge.

The alkaline earth metals have much higher melting points than the alkali metals: beryllium melts at 1287ºC, magnesium at 649ºC, calcium at 839ºC, strontium at 768ºC, barium at 727ºC, and radium at 700ºC.  They are harder metals than the Group 1A elements, but are soft and lightweight compared to many of the transition metals.

Salts of the Group 2A metals are less soluble in water than those of Group 1A because of the higher charge densities on the 2+ cations; nevertheless, many Group 2A salts are at least moderately soluble.   Some Group 2A salts bond strongly to water molecules, and crystallize as hydrates; among these are Epsom salt, MgSO4·7H2O, and gypsum, CaSO4·2H2O.

Explanation:

Answer:

H2, N2, O2, F2, Cl2, Br2, I2

Explanation:

The 7 diatomic elements in the periodic table are Hydrogen, Nitrogen, Oxygen, Fluorine, Chlorine, Bromine and Iodine.

Answer:

Chlorine-35 and chlorine-37 are not different elements because an atom of chlorine-35 and an atom of chlorine-37 each contain the same number of protons. The number of protons an atom has, also known as the atom's atomic number, determines which element it is. All atoms which contain 17 protons are called chlorine atoms. Adding or removing a proton from an atom's nucleus changes that atom's atomic number and creates a different element.

Chlorine-35 and chlorine-37 are both isotopes of the element chlorine. The number after the name 'chlorine' is called the mass number. The mass number is a tally of the number of protons and the number of neutrons in an atom's nucleus. Since all atoms of chlorine contain 17 protons, chlorine-35 and chlorine-37 differ in the number of neutrons each one has. An atom of chlorine-35 contains 18 neutrons (17 protons + 18 neutrons = 35 particles in the nucleus) while an atom of chlorine-37 contains 20 neutrons (17 protons + 20 neutrons = 37 particles in the nucleus).

Adding or removing a neutron from an atom's nucleus creates isotopes of a particular element. Why does changing the number of protons in an atom change which element that atom is but changing the number of neutrons doesn't? Protons carry a positive charge. Each proton in an atom's nucleus must be balanced with a negatively charged electron in one of the 'shells' outside the nucleus. The number of electrons in an atom's outer shell determines the atom's chemical properties. Adding or removing protons changes the number and arrangement of electrons in the outer shell which changes how that atom reacts with other atoms. Neutrons don't change things greatly because they do not carry an electrical charge. Neutrons can be added or removed from an atom and the electrons around the atom really don't care that much.

Carbon has 6 neutrons, 6 protons and 6 electrons.

Answer:

only transverse and electromagnetic waves

Explanation:

Light waves are electromagnetic waves.Electromagnetic waves or EM waves exist waves that are created as a consequence of vibrations between an electric field and a magnetic field.

In physics, electromagnetic radiation (EMR) consists of waves of the electromagnetic (EM) field, propagating via space, and having electromagnetic radiant energy. It contains radio waves, microwaves, infrared, (visible) light, ultraviolet, X-rays, and gamma rays. All of these waves form parts of the electromagnetic spectrum.

Light waves are electromagnetic waves.Electromagnetic waves or EM waves exist waves that are created as a consequence of vibrations between an electric field and a magnetic field.

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Utiliando las leyes de Newton encontraremos que la aceleración de Ana es -1.6 m/s^2.

La segunda ley de Newton dice que:

F = m*a

Fuerza es igual a masa por aceleración.

La tercera ley de Newton dice que cuando dos objetos interactuan, cadan objeto ejerce una fuerza de igual magnitud pero opuesta direccion en el otro.

Ahora veamos como aplicar esto.

Sabemos que la niña empuja al niño, asumamos que con una fuerza F.

Tendremos entonces la ecuación:

F = 20kg*(2m/s^2) = 40N

Y por la tercer ley de Newton, esta misma fuerza (pero en opuesta dirección) se aplica a la niña, entonces tendremos:

-40N = 25kg*a

-40N/25kg = a = -1.6 m/s²

La aceleración con la que retrosede la niña es -1.6 m/s²

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The reactants and products parts of a chemical equation must be balanced.

A chemical reaction is said to be balanced when the number of atoms of each element on both sides of the equation are the same.

A chemical equation consists of the reactants and the products, hence, the number of atoms on both sides must be equal for the equation to be balanced.

Therefore, the reactants and products parts of a chemical equation must be balanced.

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Answer:6.42 ppm

Explanation:ppm = (g soluto/g soluzione) ×1000000

Answer:

increase in going from left to right across a given period.

Explanation:

Nonmetals, which are found in the right-hand region of the periodic table, have relatively large ionization energies and therefore tend to gain electrons. Ionization energies generally increase in going from left to right across a given period.

hope it is helpful:)

The digestive system is made up of the gastrointestinal tract—also called the GI tract or digestive tract—and the liver, pancreas, and gallbladder. The GI tract is a series of hollow organs joined in a long, twisting tube from the mouth to the anus. The hollow organs that make up the GI tract are the mouth, esophagus, stomach, small intestine, large intestine, and anus. The liver, pancreas, and gallbladder are the solid organs of the digestive system.

The small intestine has three parts. The first part is called the duodenum. The jejunum is in the middle and the ileum is at the end. The large intestine includes the appendix, cecum, colon, and rectum. The appendix is a finger-shaped pouch attached to the cecum. The cecum is the first part of the large intestine. The colon is next. The rectum is the end of the large intestine.

Digestion is important because your body needs nutrients from food and drink to work properly and stay healthy. Proteins, fats, carbohydrates, vitamins NIH external link, minerals NIH external link, and water are nutrients. Your digestive system breaks nutrients into parts small enough for your body to absorb and use for energy, growth, and cell repair.

Each part of your digestive system helps to move food and liquid through your GI tract, break food and liquid into smaller parts, or both. Once foods are broken into small enough parts, your body can absorb and move the nutrients to where they are needed. Your large intestine absorbs water, and the waste products of digestion become stool. Nerves and hormones help control the digestive process.

Answer:

(5.00M)(X) = (0.120L)(0.470M)

X = (0.120)(0.470)/(5.00)

0.01128

Explanation:

12.1 M HNO3 would be needed to prepare 0.500 L of 0.500 M HNO3 stock solution is 0.01128 milliliters.

The ideal way to define stock solutions is as concentrated solutions with precise, known concentrations that will be diluted for later laboratory usage. Even though you may decide against making stock solutions, doing so may help you run your business more efficiently and save you a ton of time and money.

where C1 x V1 = C2 x V2. Stock concentration, C1 ( beginning concentration ) V1 is the amount of stock needed to make the new solution. C2 is the concentration of a fresh or effective solution.

( 5.00M ) ( X ) = ( 0.120 liter ) ( 0.470 M )

Then, X = 0.120 × 0.470 ÷ 5.00

= 0.01128 milliliters.

Thus, 12.1 M HNO3 would be needed to prepare 0.500 L of 0.500 M HNO3 stock solution is 0.01128 milliliters.

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Answer:

The number of electrons is the atomic number

Answer:

try using this calculator

wolfram alpha lewis structure calculator

Explanation:

The best Lewis structure, adhering to formal charge rules, of IO₄⁻, has eight bonding pairs of electrons around the iodine atom.

A Lewis Structure is a very simplified representation of the valence shell electrons in a molecule. It is used to show how the electrons are arranged around individual atoms in a molecule.

The shared pairs of electrons are drawn as lines between atoms, while lone pairs of electrons are drawn as dots next to atoms.

They also display the total number of lone pairs present in each of the atoms that constitute the molecule.

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Answer:

Reforestation can be used to undo and rectify the effects of deforestation and improve the quality of human life by absorbing pollution and dust from the air, rebuilding natural habitats and ecosystems,reducing global warming via biosequestration of atmospheric carbon dioxide, and harvesting for resources, particularly.

Explanation:

Answer:

31 miles lol

Explanation:

30 mins is half of an hour and they went 62 miles per hour so divide 62 by 2

In the gaseous state, the molecules are completely free because there is no intermolecular interaction between the molecules hence they translate at incredibly high velocity.

According to the kinetic theory of matter, the molecules that compose matter are in constant random motion. The nature of this motion varies in the three states of matter which are;

In the solid state, the molecules do not translate, they only vibrate and rotate about their mean positions. In the liquids state, the molecules translate but they still have restricted degrees of freedom due to intermolecular interactions. In the gaseous state, the molecules are completely free because there is no intermolecular interaction between the molecules hence they translate at incredibly high velocity.

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Answer:

dipole-dipole forces

Explanation:

The important intermolecular force in hydrogen iodide HI is dipole- dipole forces. This force is arising due to the partial charge separation and permanent dipole moment.

There are various intermolecular forces which binds two atoms chemically to form a compound. Ionic bonding, covalent bonding, dipole -dipole force, hydrogen bonding, Van der Waals force etc are some of them.

Dipoles are opposite charges separated by a small distance. Dipole -dipole force is generated between the atoms when they have partial charge separation and this creates a permanent dipole moment.

Hydrogen is an electropositive atom and iodine is slightly electronegative. This difference in electronegativities leads to the bonded electrons more attracted towards iodine result in partial charge separation and dipole-dipole force.

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Answer:

Explanation:

b