Answer:
Number of Significant Figures: 4
The Significant Figures are 5 4 3 9
Explanation:
does anyone know how to find the electron configuration of an element without using a periodic table?? group and period is already given
Please help. A 208 g sample of sodium-24 decays. How much of this radioactive isotope will remain after 3 half
lifes?
Answer: The information about sequential order of the event occurred in the past can be obtained by using only relative dating method.
Explanation:
Relative dating method doesn’t give information about when it happened. It provides sequential order of the events. It is the art of deciding the overall happening of past occasions (i.e., the age of an item in contrast with another), without fundamentally deciding their outright age (for example evaluated age).
In topography, shake or shallow stores, fossils and lithologies can be utilized to correspond one stratigraphic segment with another.
An atom of sodium has 11 electrons. Make a sketch of a sodium atom, showing how many electrons it has at each energy level. Infer how reactive sodium atoms are.
SOMEONE HELP ME PLEASE :(. I DONT GET IT :(
If you have 1 mol xe and 1 mol f₂, how many moles of xef₄ can you create in the following chemical reaction? xe (g) 2 f₂ (g) → xef₄ (g).
The number of moles of XeF4 that can be created would be 0.5 moles.
From the equation of the reactiobn:
Xe (g) 2 F₂ (g) ---> XeF₄ (g)
The mole ratio of Xe to F2 is 1:2. Hence, in the presence of 1 mole Xe and 1 mole F2, F2 would be limiting the reaction.
This means that the amount of F2 would determine the amount of XeF4 that would be produced from the reaction.
The mole ratio of F2 to XeF4 according to the equation is 2:1. This means that for every 1 mole of F2 introduced into the reaction, 0.5 moles of XeF4 will be produced.
In this case, 1 mole of F2 is introduced. Thus, the mole of XeF4 that would be produced would be:
1/2 = 0.5 moles.
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What are the major reservoirs for sulfur
Answer:
the ocean, the ocean floor basalts, evaporite deposits and reduced marine sediments.
Explanation:
An iron object alloyed with cobalt rusts more quickly than a pure iron object. However, an iron object alloyed with manganese rusts less quickly than a pure iron object under the same conditions. This is true because: __________
a. cobalt is a stronger reducing agent than iron
b. iron is a stronger reducing agent than manganese
c. cobalt exhibits more metallic character than either iron or manganese in the iron-manganese alloy
Rusting is an electrochemical reaction. Iron rusts faster when alloyed with cobalt than when alloyed with manganese because, in the iron-manganese alloy, manganese is rendered the anode and iron is rendered the cathode
An alloy is a combination of two metals. There are various reasons for producing alloys such as greater tensile strength, corrosion resistance and improved aesthetic appearance.
When iron is alloyed with cobalt, the iron rusts faster than pure iron because iron is rendered the anode and cobalt is rendered the cathode. When the iron is alloyed with manganese, it rusts more slowly than pure iron because in the iron-manganese alloy, manganese is rendered the anode and iron is rendered the cathode.
Missing parts;
An iron object alloyed with cobalt rusts more quickly than a pure iron object. However, an iron object alloyed with manganese rusts less quickly than a pure iron object under the same conditions. This is true because
(1) cobalt is a stronger reducing agent than iron
(2) iron is a stronger reducing agent than manganese
(3) cobalt exhibits more metallic character than either iron or manganese
(4) in the iron-manganese alloy, manganese is rendered the anode and iron is rendered the cathode
(5) in the iron-cobalt alloy, cobalt is rendered the anode and iron is rendered the cathode
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whats the formula for lithium nitride
Answer:
Lithium nitride. Trilithium nitride. 26134-62-3. Lithium nitride (Li3N) Li3N.
Choose the statement that is TRUE. Question 26 options: Outer electrons efficiently shield one another from nuclear charge. All of the answers are true Valence electrons are most difficult of all electrons to remove. Core electrons effectively shield outer electrons from nuclear charge. Core electrons are the easiest of all electrons to remove.
The statement which is true is Core electrons effectively shield outer
electrons from nuclear charge.
Core electrons are those which are in close proximity with the nucleus. The
core electrons repel the outer electrons farther away from the nucleus to
shield it from nuclear charge.
The valence electrons are usually found in the outermost part of the shell
and they are the easiest to remove due to the fact that they have to achieve
a stable octet configuration which makes them easily removed during
chemical reactions.
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Answer: core electrons effectively shield outer electrons from nuclear charge
Explanation:
Using the information in the table, calculate the number of moles in a 7.89 kg sample of aspirin
(C9H8O4).
Write your answer using three significant figures.
Answer:
43.7mol
Explanation:
[tex]?mol = 7.86kg * \frac{1000g}{1kg} *\frac{1mol}{180g}[/tex]
Above is dimensional analysis method. Write what you are trying to find with the question mark and write your given info on the other side of the equal sign. Follow the units and pay attention to them cancelling out. You should have your answer unit by the end.
the 180g came from the table with masses times the chemical formula all added together. Below is exact formula.
hydrogen mass(hydrogen amount) + carbon mass(carbon amount) + oxygen mass(oxygen amount)
1g(8)+12g(9)+16g(4)=180g
180g is 1 mole of [tex]C_{9} H_{8} O_{4}[/tex]
Which is an example of a physical change?
A) Mixing blue and yellow paint to create green paint
B) Adding water and yeast to bread dough in order to make it raise.
C) Mixing two liquids together in a test tube and the tube becoming warm.
D) Adding a piece of chalk containing calcium carbonate to a glass of mild acid causing the information of a foam of bubbles.
what is temperature?
Answer:
a measure of hotness or coldness expressed in terms of a scale like Fahrenheit or Celcius
Electrons are shared. Is it Ionic bond, covalent bond or both?
Answer:
covalent bond
Explanation:
ionic bond is when electrons are transferred by atoms not shared
True or false: For a spontaneous redox reaction, the products are stronger oxidizing and reducing agents than the reactants.
Answer: False
Explanation: The stronger oxidizing agent, and stronger reducing agent are the reactants.
The given statement is false , for a spontaneous redox reaction, the reactants are stronger oxidizing and reducing agents than the products.
What are redox reactions?Redox reactions comprise of two parts a reduced part and an oxidized part, which occur simultaneously . The part which is reduced gain electrons and hence there is a increase in oxidation state of the species.
While, the part which is oxidized looses electrons and hence there is a decrease in oxidation state of the species.During redox reactions, there is no net change in the number of electrons . Electrons which are given off in oxidation are used up in reduction.
The ion or molecule which accepts electrons is called as oxidizing agent while the ion or molecule which donates electrons is called as a reducing agent.
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Which of the following best describes the cell below
plant cell
Protist cell
Eukaryotic cell
Prokaryotic cell
Answer:
Prokaryotic cell
Explanation:
If you search it up you will see that the prokaryotic cell looks exactly alike with the picture you have posted.
Define ionic bond and explain the formation of nacl and mgo
a.
Ionic bond is a bond in which there is complete transfer of valence electrons between atoms.
The atom that loses the valence electron is called the electron donor while the atom that accepts the electron is called the electron acceptor.
Ionic bond usually occurs between metals and non metals.
Ionic bond is a bond in which there is complete transfer of valence electrons between atoms.
b.
The force of attraction between Na⁺ and Cl⁻ forms the ionic bond.
In the formation of NaCl, Na has one valence electron in its outermost shell and Cl needs one electron to complete the stable octet configuration. Na donates its valence electron to Cl to form the ionic bond. So, the Na atom becomes positively charged with a charge of +1 while the Cl atom becomes negatively charged with a charge of -1.Since the atoms are now charged, the force of attraction between them forms the ionic bond.
c.
The force of attraction between Mg²⁺ and O²⁻ forms the ionic bond.
In the formation of MgO, Mg has two valence electrons in its outermost shell and O needs two electrons to complete the stable octet configuration. Mg donates its two valence electron to O to form the ionic bond. So, the Mg atom becomes positively charged with a charge of +2 while the O atom becomes negatively charged with a charge of -2.Since the atoms are now charged, the force of attraction between them forms the ionic bond.
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An ionic or electrovalant bond is a type of chemical bond, which is formed from two ions (charged atoms by loosing or gaining electrons) having opposite charges.
Ionic bonds are formed from the transfer of electrons from one atom to another. As the electrons are transferred there occurs a positively charged ions (cations) and a negatively charged ions (anions). These ions are held together in a crystal lattice structure by the strong electrostatic attraction between the positively charged cations and negatively charged anions.
The electrons are transferred as the atoms have tendencies to achieve a stable electronic configuration. They do this to attain a stable atomic structure. By transferring the electrons they attain their octet or duplet.
Sodium chloride(NaCl) is formed when the atom of sodium combines chemically with chlorine atom to generate an ionic compound.
Since sodium has an atomic number of 11, its electronic configuration is 2, 8, 1. There is only one electron in the outermost shell of a sodium atom. Therefore, the sodium atom gives one electron to produce the sodium ion Na⁺.
Chlorine has an atomic number of 17. Hence, its electronic configuration is 2, 8, and 7. The chlorine atom contains seven electrons in its outermost shell and requires one more electron to create the inert gas’s stable, eight-electron configuration. Consequently, a chlorine atom accepts one electron and creates the negatively charged chloride ion (Cl⁻).
When sodium interacts with chlorine, it donates its outermost electron to the chlorine atom, forming a sodium ion (Na⁺) and a chloride ion (Cl⁻) by accepting an electron. The strong electrostatic force of attraction between the newly created ions, holds sodium and chloride ions together to create sodium chloride, Na⁺Cl⁻ or NaCl.
Similarly in the case of Magnesium Oxide (MgO) is formed from the chemical interactions of Magnesium and oxygen atoms, leading to the formation of an ionic compound.
Since magnesium has an atomic number of 12, its electrical configuration is 2, 8 and 2, there is just 2 electrons in the outermost shell of a Magnesium atom. Therefore, the magnesium atom gives two electron to produce the Magnesium ion Mg²+ .
Oxygen has an atomic number of 8. Hence, its electronic configuration is 2 and 6, the oxygen atom contains 6 electrons in its outermost shell and requires 2 more electron to create the inert gas’s stable, eight-electron configuration. Consequently, a oxygen atom accepts 2 electronelectrons and creates the negatively charged oxide ion (O²-).
When magnesium interacts with oxygen, it donates its outermost electrons to the oxygen atom, generating a Magnesium ion Mg²+ . And an oxygen ion (O²⁻) by acquiring 2 electrons. The attractive electrical force holds magnesium and oxygen ions together to create sodium chloride, Mg²⁺ O²⁻ or MgO.
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Determina la molaridad de una solución de H2S, si se colocaron 37 ml del ácido en 890 ml de solución. La densidad del H2S es de 1.36 g/ml
Por definición de molaridad y densidad, la molaridad de la solución es 1.66 [tex]\frac{moles}{litros}[/tex].
La concentración molar o molaridad es una medida de la concentración de un soluto en una disolución que indica el número de moles de soluto que están disueltos en un determinado volumen.
La molaridad de una solución se calcula dividiendo los moles del soluto por el volumen de la solución:
[tex]Molaridad=\frac{numero de moles de soluto}{volumen}[/tex]
La Molaridad se expresa en las unidades [tex]\frac{moles}{litros}[/tex].
Por otro lado, la densidad es una magnitud que permite medir la cantidad de masa que hay en determinado volumen de una sustancia.
Entonces, la expresión para el cálculo de la densidad es el cociente entre la masa de un cuerpo y el volumen que ocupa:
[tex]densidad=\frac{masa}{volumen}[/tex]
En este caso, siendo H₂S el soluto, se colocaron 37 ml del ácido, siendo su densidad 1.36 [tex]\frac{g}{mL}[/tex]. Reemplazando en la definición de densidad se obtiene:
[tex]1.36\frac{g}{mL}=\frac{masa}{37 mL}[/tex]
masa= 1.36 [tex]\frac{g}{mL}[/tex]× 37 mL
masa= 50.32 g
Siendo 34 g/mol la masa molar de H₂S, es decir la cantidad de masa que una sustancia contiene en un mol, la cantidad de moles de H₂S puede ser calculada como:
[tex]numero de moles de H_{2}S= 50.32 grams\frac{1 mole}{34 grams}[/tex]
número de moles de H₂S= 1.48 moles
Siendo 890 mL=0.890 L el volumen de la solución, entonces la molaridad puede ser calculada como:
[tex]Molaridad=\frac{1.48 moles}{0.890 L}[/tex]
Molaridad= 1.66 [tex]\frac{moles}{litros}[/tex]
Finalmente, la molaridad de la solución es 1.66 [tex]\frac{moles}{litros}[/tex].
Aprende más:
https://brainly.com/question/17647411?referrer=searchResultshttps://brainly.com/question/21276846?referrer=searchResultsWhich ingredients are needed to transform nadp to nadph?.
Answer:
according to online:
"Hydrogen ions are transported with the electrons along the chain of reactions. In photosystem I, the electrons are energized, and the energy is stored in molecules of NADP+. During these reactions, the NADP+ molecules are reduced by the addition of electrons. A hydrogen ion is added to NADP+ to form NADPH."
Explanation:
hope this helps!! :)
A solution containing cacl2 is mixed with a solution of li2c2o4 to form a solution that is 2. 1*10^-5m in calcium ion and 4. 75*10-5 m in oxalate ion. What will happen once these solutions are mixed?\.
Answer:
the answer is d
Explanation:
i know
Help ASAP!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!:)
Correct:
Delivers Nutrients to cells Removes waste materials from cellsProtects the body from pathogensHelps cuts and wound to heal.Incorrect:
Brings carbon dioxide to cells for use.Carbon dioxide is the waste product of cells that you let out each time you breathe.
How does a phase change from solid to liquid occur in a substance?
A. Heat energy is released from the substance, weakening the electrical attraction between molecules.
B. Heat energy is released from the substance, strengthening the electrical attraction between molecules.
C. Heat energy is added to the substance, weakening the electrical attraction between molecules.
D. Heat energy is added to the substance, strengthening the electrical attraction between molecules.
Answer:
see below
Explanation:
1. Heat energy is added to the substance, weakening the electrical attraction between molecules.
2. Both the melting point and boiling point are lower.
3. dipole
4. Water and ethanol have different molecular structures.
5. The lone pairs of electrons in the oxygen atom causes the molecule to be bent; the oxygen atom has a partial negative charge, while the hydrogen atoms have partial positive charges.
[quizlet: captncrun]
Heat is a form factor that changes the solid from light to light to gaseous mediums. The phases take place in a cyclic manner.
The solid to liquid changes take place due to the melting or fusion, solid to gas take lace through the sublimation, liquid to gas is by vaporization, and gas to liquid is condensation. Thus the heat is added and leads to the weakening of the electrical attraction within the molecules.Hence the correct option is C.
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Which one of the following would form a precipitate when mixed with LiOH?
A) KNO3
B) NH4Cl
C) Ca(C2H3O2)2
D) ZnBr2
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
Precipitation reactionsThese 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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What is the frequency of light with a wavelength of 450 nm?
Answer:
The frequency of blue light that has a wavelength of 450 nm is 6.7×1014 6.7 × 10 14 Hz.
Explanation:
BRAINLIEST?
Why is the Milky Way considered a galaxy
Answer:
Explanation:
All the stars we see in the night sky are in our own Milky Way Galaxy. Our galaxy is called the Milky Way because it appears as a milky band of light in the sky when you see it in a really dark area.
Answer: it is
Explanation: A galaxy is a system of millions or billions of stars, together with gas and dust, held together by gravitational attraction, plus there are 100 billion planet in it.
Explain why copper has a high thermal conductivity.
Explain why copper has a high electrical conductivity.
i just need like a basic explanation for an essay
Explanation:
So copper is a lattice of positive copper ions with free electrons moving between them.
when calculating specific heat what if the change in temperature is negative?
Answer:
If AT and q are negative, then heat flows from an object into its surroundings. If a substance gains thermal energy, its temperature increases, its final temperature is higher than its initial temperature, then AT>0 and q is positive.
Rank the following molecules (1st, 2nd, 3rd, 4th) in the order that they melt.
Sucrose
Iodine
Sodium
Paraffin
There is a picture attached
Sodium chloride has the highest melting point while iodine has the least melting point.
The melting points of solid substances depends on the nature of intermolecular forces that exists in the substance. The stronger the magnitude of intermolecular forces in a substance, the higher its melting point.
The order of melting points of the solids shown in question is as follows;
1st - Sodium chloride2nd - sucrose3rd - paraffin4th - IodineSodium chloride has the highest melting points because it is an ionic substance. Among the molecular sucrose and paraffin, sucrose has a higher melting point than sucrose because it has a greater molar mass. Iodine, a molecular substance has the least molar mass and the least melting point in the list.
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Help
What is the correct orientation of the bar magnet, based on the magnetic field
lines shown?
A. South pole on the top edge and north pole on the bottom edge.
B. North pole on the top edge and south pole on the bottom edge
C. South pole on the left end and north pole on the right end
D. North pole on the left end and south pole on the right end
Answer:
b
Explanation:
north is up south is bottom
Answer:
C. South pole on the left end and north pole on the right end
Explanation:
From the figure, we can conclude that the poles of the magnet are on either sides of the magnet
Therefore, options 1 and 2 are excluded
It is a convention that the magnetic field lines move out of the north pole of a magnet and into the south pole of the magnet
From the figure, we can see that the magnetic field lines are moving out from the right end and into the left end
This means that the north pole is at the right end and that the south pole is at the left one
When light waves pass through solids, the speed of the wave ___________.
remains the same
decreases
increases
It woukd decrease.
I am sure its correct you can trust me becuase I took the test.
Answer:
The speed of the wave decreases.
Explanation:
When light waves do pass through a medium, any solid, liquid, or gas, the speed of the waves actually decreases. Solids are more dense than liquids, so they decrease the speed of light even more.
(I did the quiz btw!!)
Find the volume v of the solid obtained by rotating the region bounded by the given curves about the specified line. Y = 8x3, y = 0, x = 1; about x = 2.
The volume v of the solid obtained is 15.08
By using the cylindrical shell method to find the volume v of the solid which can be expressed by the formula;
V = 2πrh drThen, it is paramount to determine the radius and height of the shell.
From the given information;
The cylindrical shell formed by the rotation about the line x = 2Let consider the radius to be 2 - xThe circumference = 2π(2 - x)The height = 8x³Then, the volume v of the solid can be estimated by using the cylindrical shell method as follows;
[tex]\mathbf{V = \int ^1_0 2 \pi (2-x) (8x^3) \ dx}[/tex]
Open brackets;
[tex]\mathbf{V = 2 \pi \int ^1_0 (16x^3 -8x^4) \ dx}[/tex]
Taking the integral form;
[tex]\mathbf{V = 2 \pi \Big [ \dfrac{16x^4}{4}-\dfrac{8x^5}{5} \Big]^1_0}[/tex]
Solving the terms in the bracket
[tex]\mathbf{V = 2 \pi \Big [ \dfrac{16(1)^4}{4}-\dfrac{8(1)^5}{5} -0\Big]}[/tex]
[tex]\mathbf{V = 2 \pi \Big [ 4-\dfrac{8}{5} \Big]}[/tex]
[tex]\mathbf{V = 2 \pi \Big [ \dfrac{20-8}{5} \Big]}[/tex]
[tex]\mathbf{V = 2 \pi \Big [ \dfrac{12}{5} \Big]}[/tex]
[tex]\mathbf{V = \dfrac{24\pi}{5}}[/tex]
[tex]\mathbf{V =15.08}[/tex]
Therefore, we can conclude that the volume v of the solid obtained is 15.08
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A bar of copper (Copper = 0.385 J/g.°C) and a bar of aluminum (Aluminum = 0.897 J/g.°C) have the same mass. Which requires more energy to increase the temperature from 20°C to 30 °C?
Answer:
Aluminum
Explanation:
