Answer:
93.75
Explanation:
In first half life 750×1/2 will remain
In second one half from that remained at the end of first half life will remain
That is 1/2 × 750×1/2
likewise at the end of 3rd half life 1/2 × 1/2 ×750×1/2 remains
at the end of 4th half life 1/2 × 1/2 × 1/2 ×750×1/2 remains
1/2 × 1/2 × 1/2 ×750×1/2 = 93.75 remains.
You can also use the equation
Remainder = X × 1/2^n .
This saves time
n= no. of half lives
X= initial amount
so in this case 1/2^4 × 750 = 93.75
What is atomic mass? the mass of the atom based on the mass of an atom of hydrogen-1 the mass of an atom based on the mass of an atom of carbon-12 the mass of the atom based on the mass of an atom of oxygen-16 the mass of an atom based on the number of electrons
Answer:
The mass of an atom based on the mass of an atom of carbon-12
Explanation:
2. What mass of water absorbs 6700 J of heat to raise the temperature from 283K to 318K?
Answer:
Q = mcT ...you can either substitute the molar heat capacity of water in the place of c or the specific heat capacity of water.
Explanation:
what is the periodic trend for electronegativity
Answer:
mark me brainlest
Explanation:
Electronegativity values generally increase from left to right across the periodic table. Electronegativities generally decrease from top to bottom of a group. The highest electronegativity value is for fluorine.
Answer:
"Electronegativity increases as you move from left to right across a period because the number of charges on the nucleus increases." (sstudy30 on Quizlet)
Explanation:
It explains itself haha!
Have a nice day!
I hope this is what you are looking for, but if not - comment! I will edit and update my answer accordingly. (ノ^∇^)
- Heather
The half-life of Palladium-100 is 4 days. After 16 days a sample of Palladium-100 has been reduced to a mass of 6 mg. What was the initial mass (in mg) of the sample
Answer:
96mg
Explanation:
Since the half-life of Palladium-100 is 4 days and the sample has been reduced after 16 days, that means the sample has undergone four half-lives. To find the intial mass, just work backwards:
6 x 2= 1212 x 2= 2424 x 2= 48 48 x 2= 96As you see, I've worked backwards from the four half-lives. So the initial mass after 16 days is 96 mg.
explain the factors that affect the separation of mixtures in amino acids
The measurable properties of a substance, such as vapor pressure and surface tension, occur due to the strength of
electrical forces between particles, as given by Coulomb's law
electrical forces between particles, as given by Newton's law
gravitational forces between particles, as given by Newton's law
O gravitational forces between particles, as given by Coulomb's law
Answer:
electrical forces between particles, as given by coulombs law.
Explanation:
Properties of a substance such as vapor pressure and surface tension depend on electrical forces between particles, as given by Coulomb's law.
The vapor pressure refers to how easily a liquid converts to gas while surface tension is the force that makes a liquid surface act as a stretched elastic skin.
Both vapor pressure and surface tension has a lot to do with the degree of polarity in a molecule. Usually, polar molecules have a low vapor pressure and high surface tension due to a high electrical forces between particles, as given by Coulomb's law.
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MULTIPLE CHOICE QUESTION
Which of the above represents a cell in an
isotonic solution?
B
А
C
Answer:
B
Explanation:
Why do metals form cations and nonmetals form anions?
[tex]▪▪▪▪▪▪▪▪▪▪▪▪▪ {\huge\mathfrak{Answer}}▪▪▪▪▪▪▪▪▪▪▪▪▪▪[/tex]
Metals have tendency to loose electrons in order to get noble gas configuration, therefore they loose electrons to form Cations (positively charged ions)
for example ~ Sodium forms Na+
And
Non - metals have tendency to gain electrons in order to attain noble gas configuration , hence they gain electron from somewhere and bears a negative charge forming Anion.
for example ~ Chlorine forms Cl-
Monica put four items on the desk that you need to measure the mass of. The items are listed below. Which of the following would need to be put in a container in order to measure the mass on a scale?
I. Flour
II. Sugar cubes
III. Milk
IV. An unbroken egg
A. I and III
B. I and IV
C. II and III
D. III and IV
Answer:
it D because it make more sense
The electron configuration of na atom is 2,8,1. Give the electronic configuration of C D G H
Answer:
Explanation:
Record the letters in your triangle from left to right A MAGNESIUM CHLORATE B MAGNESIUM SULFATE C MAGNESIUM HYPOCHLORIDE D MAGANESE PERCHLORATE E MN C10 F MGMNO G MANGANESE CHLORIDE
Explain why some metals are extracted by heating their oxides with carbon, but some metals cannot be extracted in this way
Answer:
This happens because a metal is less reactive than carbon and it can be extracted from its oxides by heating with carbon. The carbon displaces metal from the compound and removes the oxygen from the oxide.
In a star, nuclear fusion occurs in the
A. core
B. radiative zone
C. photosphere
D. corona
Answer:
A. Core
Explanation:
The collisions which occur between the hydrogen atoms starts to heat the gas in the cloud. Once the temperature reaches 15,000,000 degrees Celsius, nuclear fusion takes place in the center, or core, of the cloud. The tremendous heat given off by the nuclear fusion process causes the gas to glow creating a protostar.
In a star, nuclear fusion which is a type of nuclear reaction occurs in the core.
What are nuclear reactions?There are two types of nuclear reactions which are nuclear fusion and nuclear fission .They involve the combination and disintegration of the element's nucleus respectively.
In nuclear fission, the nucleus of the atom is bombarded with electrons of low energy which splits the nucleus in to two parts .Large amount of energy is released in the process.It is used in nuclear power reactors as it produces large amount of energy.
In nuclear fusion,on the other hand, is a reaction which occurs when two or more atoms combine to form a heavy nucleus.Large amount of energy is released in the process which is greater than that of the energy which is released in nuclear fission process.
Learn more about nuclear reactions,here:
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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.
Learn more about the phase change from solid to liquid occur in a substance
brainly.com/question/25664350.
complete the word equations below to show how the metals are extracted from their oxides: 1) tin oxide + carbon ---> .........? + .......? 2) lead oxide + carbon ----> ......? + ......?
Answer:
1.) Tin oxide + Carbon → Tin + Carbon monoxide.
2.) Lead oxide + Carbon → Lead + Carbon monoxide.
These equations show that the metals are being extracted by their oxides by heating with carbon. This is because the metals (Tin and Lead) are less reactive than carbon. Remember, extraction methods of metals are determined by their reactivity. Since the elements tin and lead are less reactive than carbon, the extraction process of heating with carbon is needed. Remember that when a metal heats with carbon, the carbon displaces the metal from the compound and removes the oxygen from the oxide. Leaving you with the metal and carbon monoxide.
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.
More on stoichiometric calculations can be found here: https://brainly.com/question/8062886?referrer=searchResults
list of charge of elements that do not form compound easily
Answer:
The highlighted words in the explanation.
Explanation:
A clue comes by considering the noble gas elements, the rightmost column of the periodic table. These elements—helium, neon, argon, krypton, xenon, and radon—do not form compounds very easily, which suggests that they are especially stable as lone atoms. What else do the noble gas elements have in common?
How many moles are present in 1.39 grams of carbon?
C
R. F. M (Relative Formula Mass) of C=12
12g of C=1 mole
1.39g of C=(1*1.39)/12
=0.1158 moles
what type of bacteria use the enzyme nitrate reductase to metabolize nitrogen oxides and transform them back to nitrogen gas?
Denitrifying Bacteria such as Pseudomonas aeruginosa is the type of bacteria that use enzyme nitrate reductase to metabolise nitrogen oxides to nitrogen gas.
Denitrification is the process whereby nitrites or nitrogen oxides is converted to nitrogen gas by a denitrifying Bacteria such as Pseudomonas.
Pseudomonas aeruginosa uses enzyme nitrate reductase to reduce nitrate to nitrite.
Then nitrite is then converted back to nitrogen gas.
Therefore, Pseudomonas aeruginosa is a type of bacteria that uses enzyme nitrate reductase.
Two cars leave from Houston to go to different destinations. Car 1 travels at 62 mph for 30 minutes. How far did car 1 travel?
Answer:
31 miles lol
Explanation:
30 mins is half of an hour and they went 62 miles per hour so divide 62 by 2
How many deciseconds are
in 554 seconds?
Give your answer in standard form.
Answer:
5540
Explanation:
Answer:
5,440
Explanation:
10 deciseconds = 1 seconds
554 seconds = 5,440 seconds
How do you find the frequency of a recorder?
Answer:
Modern recorders are most commonly pitched at A=440 Hz, but among serious amateurs and professionals, other pitch standards are often found. For the performance of baroque music, A=415 Hz is the de facto standard, while pre-Baroque music is often performed at A=440 Hz or A=466 Hz.
Explanation:
asap help for brainlst
List the 7 diatomic elements in the periodic table.
Question 5 options:
All alkaline earth metals- Be, Mg, Ca, Sr, Ba,Ra.
All elements in the periodic table are diatoms.
H2, N2, O2,F2, Cl2, Br2, I2
All group 16 elements-O, S, Se, Te, Po.
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.
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=searchResultsTRUE or FALSE the term “anti-inflammatory” likely means “against inflammation”
Answer:
True
ANTI MEANS AGAINST
Explanation:
How is heat transferred when a person holds a pen that is already at body
temperature?
A. From the hand to the pen
B. Heat is not transferred.
C. In both directions between the pen and the hand
D. From the pen to the hand
SUBMIT
Answer:
The answer is B.
Explanation:
Heat is not transferred.
doy CORONITA a quien me ayude rapido que es un examen porfaaa
Answer:
thank you for the points
When a bat hits a ball, what is the impulse?
a. the change in velocity multiplied by the force
b. the force multiplied by the time objects are in contact
c. the mass multiplied acceleration
d. the mass multiplied by the force
Answer:
The answer is B.
Explanation:
the force multiplied by the time objects are in contact
1. Why fractional distillation has
fractionating column but not in simple
distillation?
Answer:
fractional distillation leads to better separation
What is the maximum number of electrons in the following energy level? n = 1
Maximum number of electrons in nth energy level
[tex]\\ \sf\longmapsto 2n^2[/tex]
Now
n=1Max electrons
[tex]\\ \sf\longmapsto 2(1)^2[/tex]
[tex]\\ \sf\longmapsto 2e^-[/tex]
What is the common name for N2O? mononitrogen dioxide dinitrogen monoxide nitrogen oxide nitrous oxide.
Considering the IUPAC name, the common name for N₂O is nitrous oxide
IUPAC (International Union of Pure and Applied Chemistry), is the recognized authority in the development of standards for the naming of chemical compounds, through their Interdivisional Commitee on Nomenclature and Symbols.
The IUPAC name to N₂O is nitrous oxide. Nitrous oxide is commonly known as the laughing gas is a colorless gas with a pleasant, sweetish odor and taste that, when breathed, causes placidity to pain.
Learn more:
https://brainly.com/question/25759961https://brainly.com/question/23036094?referrer=searchResultshttps://brainly.com/question/25759613Answer:
on e2020 the first one is dinitrogen monoxide second one is nitrous oxide
Explanation:
