Answer:
[tex]23.32\ \text{days}[/tex]
Explanation:
N = Final mass of atom = 125 g
[tex]N_0[/tex] = Initial mass of atom = 16000 g
t = Time taken = 163.24 days
[tex]t_{1/2}[/tex] = Half life
We have the relation
[tex]N=N_0\dfrac{1}{2}^{\dfrac{t}{t_{1/2}}}\\\Rightarrow 125=16000\times \dfrac{1}{2}^{\dfrac{163.24}{t_{1/2}}}\\\Rightarrow \dfrac{125}{16000}=\dfrac{1}{2}^{\dfrac{163.24}{t_{1/2}}}\\\Rightarrow \ln0.0078125=\dfrac{163.24}{t_{1/2}}\ln0.5\\\Rightarrow t_{1/2}=\dfrac{163.24\times\ln0.5}{\ln0.0078125}\\\Rightarrow t_{1/2}=23.32\ \text{days}[/tex]
The half life of the atom is [tex]23.32\ \text{days}[/tex].
Which of the following best explains why the
Gastropod is not a good example of an index
fossil?
Answer:
Since the gastropod is not unique, it cannot be an index fossil. An index fossil must be found over a wide area of the Earth. Since the gastropod is widely spread, it cannot be an index fossil.
Explanation:
Un móvil se mueve con movimiento acelerado. En los segundo 2 y 3 los espacios recorridos son 90 y 120 m, Calcula la velocidad inicial y su aceleración
Answer:
La velocidad inicial es 55 [tex]\frac{m}{s}[/tex]y su aceleración es -10 [tex]\frac{m}{s^{2} }[/tex]
Explanation:
Un movimiento es rectilíneo uniformemente variado, cuando la trayectoria del móvil es una línea recta y su velocidad varia la misma cantidad en cada unidad de tiempo . Dicho de otra manera, este movimiento se caracteriza por una trayectoria que es una línea recta y la velocidad cambia su módulo de manera uniforme: aumenta o disminuye en la misma cantidad por cada unidad de tiempo. Y la aceleración es constante y no nula (diferente de cero).
En este caso la posición del objeto esta dada por la expresión:
[tex]x=x0+v0*t+\frac{1}{2} *a*t^{2}[/tex]
donde x es la posición del cuerpo en un instante dado, x0 la posición en el instante inicial, v0 la velocidad inicial y a la aceleración.
En este caso, por un lado podes considerar:
x= 90 mx0= 0 mv0= ?t= 2a= ?Reemplazando obtenes:
[tex]90=v0*2+\frac{1}{2} *a*2^{2}[/tex]
[tex]90=v0*2+\frac{1}{2} *a*4[/tex]
[tex]90=v0*2+2*a[/tex]
Y por otro lado tenes:
x= 120 mx0= 0v0= ?t= 3a= ?Reemplazando obtenes:
[tex]120=v0*3+\frac{1}{2} *a*3^{2}[/tex]
[tex]120=v0*3+\frac{1}{2} *a*9[/tex]
[tex]120=v0*3+\frac{9}{2} *a[/tex]
Por lo que tenes el siguiente sistema de ecuaciones:
[tex]\left \{ {{2*v0+2*a=90} \atop {3*v0+\frac{9}{2} *a=120}} \right.[/tex]
Resolviendo por el método de sustitución, que consiste en aislar en una ecuación una de las dos incógnitas para sustituirla en la otra ecuación, obtenes:
Despejando v0 de la primera ecuación:
[tex]v0= \frac{90-2*a}{2}[/tex]
Reemplazando en la segunda ecuación:
[tex]120=\frac{90-2*a}{2} *3+\frac{9}{2} *a[/tex]
Resolviendo:
[tex]120=(90-2*a)*\frac{3}{2} +\frac{9}{2} *a[/tex]
[tex]120=135-3*a +\frac{9}{2} *a[/tex]
[tex]120-135=-3*a +\frac{9}{2} *a[/tex]
[tex]-15=\frac{3}{2} *a[/tex]
[tex]\frac{-15}{\frac{3}{2} } =a[/tex]
-10=a
Reemplazando el valor de a en la expresión despejada anteriormente obtenes:
[tex]v0= \frac{90-2*(-10)}{2}[/tex]
Resolviendo:
[tex]v0= \frac{90+20}{2}[/tex]
[tex]v0= \frac{110}{2}[/tex]
v0=55
La velocidad inicial es 55 [tex]\frac{m}{s}[/tex]y su aceleración es -10 [tex]\frac{m}{s^{2} }[/tex]
Will mark brainliest for who is right
Which properties change the composition of a substance?
chemical and physical properties
neither chemical nor physical properties
physical properties
chemical properties
How can we predict melting points?
Explanation:
Many of the properties of organic molecules can be predicted based on the strength of their cohesive molecule-molecule interactions (i.e. how much the molecules want to stick together). The boiling point (BP) and melting point (MP) of an organic molecule is related to: 1) the molecular weight of the molecule and 2) the "stickiness" of individual molecules for their neighbors.
For example, molecules in a liquid are held together by attractive interactions between molecules. These interactions must be broken (by adding heat) in order to transition into the gas. The stronger the cohesive interactions, the more heat that is necessary for the liquid-to-gas phase transition. These same attractive molecule-molecule interactions have to be broken for a solid to liquid phase change.
Examples: (Rank the following molecules in terms of MP and BP.)
Introduction to intermolecular forces:
All of the attractive intermolecular forces are based on the electrostatic attraction of positive charges on one molecule with negative changes. The stronger the charges, the stronger the attraction between molecules.
How to:
In general, comparisons can only be made between molecules with similar formulas or molecular weights.* First, identify the functional groups in the molecules being compared. Each functional group can form different types of intermolecular interactions (see the chart above). Interactions higher up on the chart form stronger cohesive interactions and will have higher boiling points and melting points.
* Note that larger molecules usually have higher boiling points and melting points. This is not because of their higher molecular weights but because they usually have greater surface areas with which to form more intermolecular interactions. This is also why linear molecules tend to have higher MPs and BPs than branched (or more spherically shaped) molecules. Linear molecules will have more surface area than a more spherically shaped molecule.
All three molecules have approximately the same molecular formula and molecular weights. Only molecule A contains a strongly polarized or ionic functional group: an aldehyde. The C=O group in aldehydes generate a strong molecular dipole (partial + and - charges). Thus, it can form weak attractive dipole-dipole interactions, and A will have the highest boiling point and highest melting point in this series of compounds.
Molecules B and C are alkanes. They can only form the weakest attractive dispersion interactions between their molecular surfaces. Due to its long-thin shape, B will have a greater surface area and can form more dispersion interactions than the rounder C. Therefore, B will have a higher boiling point and melting point than C.
Molecule A is ionic (it has charges). Therefore, it can form the strongest ion-ion interactions and will have the highest boiling point and melting point.
Molecule B is a carboxylic acid with an acidic proton and basic lone pairs. Therefore, it can form medium strength hydrogen bonding interactions, and it will have the next highest boiling point and melting point.
Molecule C is a carboxylic ester, which is a polar functional group. However, it does not have an acidic proton. Therefore, esters cannot form hydrogen bonds with themselves. Instead, they can only form weak dipole-dipole interactions and will have the lowest boiling point and melting point in this series of compounds.
Answer:
Explanation:
By thinking about non covalent intermolecular interactions, we can also predict relative melting points. All of the same principles apply: stronger intermolecular interactions result in a higher melting point.
Which best describes the current model of the atom?
O A a central nucleus containing protons with electrons orbiting in specific paths
O B. a solid sphere unique for everything that exists
O c a solid sphere with electrons and protons embedded
O D. a central nucleus containing protons and neutrons with electrons orbiting in levels of high probability
Explanation:
i think the answer might be D
GIVING BRAINLYYY
Use the general trends of the periodic table to answer the following question.
Platinum (Pt) and gold (Au) are sometimes called noble metals because they are less reactive than other metals. Based on this evidence and the periodic table, which other element is likely to be less reactive?
According to the electronic configuration, along with platinum and gold silver is considered to be a noble metal.
What is electronic configuration?
Electronic configuration is defined as the distribution of electrons which are present in an atom or molecule in atomic or molecular orbitals.It describes how each electron moves independently in an orbital.
Knowledge of electronic configuration is necessary for understanding the structure of periodic table.It helps in understanding the chemical properties of elements.
Elements undergo chemical reactions in order to achieve stability. Main group elements obey the octet rule in their electronic configuration while the transition elements follow the 18 electron rule. Noble elements have valence shell complete in ground state and hence are said to be stable.
Learn more about electronic configuration,here:
https://brainly.com/question/29757010
#SPJ2
I WILL GIVE A LOT OF EXTRA POINTS. PLEASE ANSWER ALL OF THEM
75 for all
Explanation:
Answer:
Explanation: Li= Lithium, Na= Sodium, K= Pottasium, Rb= Rubdium Cs= Cesiuna, Fr= Fransium
6. Energy levels increases as if you move down a group during the number of electrons increases again.
7. A charge with higher and effective nuclear charge makes greater attractions to the electrons, pulling the electrons cloud closer to the nucleus makes it in a smaller atomic radius.
8. Ge= Germanium, He= Helium, O=Oxygen, Barium
Which of the following represents the chemical reaction of benzene and nitric acid to produce nitrobenzene and water?
Answer:
D
Explanation:
i mean it's just taking the words of the question and putting them into an equation
[tex]\huge\boxed{Option C}[/tex]
_____________________________________Equation:Benzene + Nitric Acid ---------> Nitrobenzene + water_____________________________________Explanation:As per Question,
It is saying that Benzene(organic compound) reacts with nitric acid. So,
Benzene and Nitric Acid are Reactants,
Nitrobenzene is the Product.
_________________________________________________________
General way of showing the reaction is,
Reactants --------> ProductIn the following Question,
Benzene is Reactant no. 1,
Nitric Acid is Reactant no.2,
Nitrobenzene is Product no 1,
Water is a By Product.
_____________________________________Best Regards,'Borz'gasoline is separated from crude oil by heating it until it reaches it's boiling point. which separation method is used?
Answer:
Fractional distillation
Explanation:
The separation of gasoline from crude oil by heating until it reaches its boiling point is a separation technique called fractional distillation.
It is the separation of a mixture, such as crude oil into their respective fractions. This is achieved due to the differences in boiling point between the constituent fractions in the mixture. As the boiling point of a fraction is reached, it distills out from the column.what is hard water and what causes hardness of water
Answer:
hard water is ice
Explanation:
ice is formed as the water temperature decreases and then it freezes
Which of the following would be considered a derived unit? A) length B mass C) density D) temperature
Answer:
density because it S.I unit is derived from fundamentals
how can animal fossils help us understand the earth
Answer:
Some animals and plant are only known to us as fossils. hope this helps. and have a nice day:)
Which is heavier, calcium or selenium?
Answer:selenium
Explanation:
Answer: Nether
Explanation: Because if you have one pound of Calcium and one pound of selenium there both the same weight
Which of the following materials would probably be used as a conductor of electric current in a computer chip?
A rubber
B. glass
c. plastic
D. gold
Answer:
gold is metal which is a very good conductor for electric current and most chips are made out of it.
Answer:
The answer is D. gold
Explanation:
What type of clothing would you need to wear if you could visit the mesosphere
The type of clothe that you would wear when visiting the mesosphere are the winter clothes.
What is mesosphere?Mesosphere is used to describe the coldest part of the earth whose temperature is -85°C.
An individual that wants to visit such a cold area should wear clothes that would provide such with warmth such as the winter clothes.
Learn more about mesosphere here:
https://brainly.com/question/237087
#SPJ1
How could you explain why soap is able to clean the oil and dirt off your bodies?
Answer:
When you wash your hands with soap, it dislodges the dirt, grease, oils, and disease-ridden fecal matter particles on your hands by creating these micelles. Surrounded by the soap, the oil molecules become suspended and distributed in the water rather than stubbornly clinging to your skin.
Explanation:
What does it mean when there is a physical change?
Question 1 options:
A new substance has been formed.
Matter has changed size, shape or form.
Matter has changed from one substance into another.
Matter has changed on the molecular level.
Answer:
The matter has changed size, shape, or form.
Explanation:
A new substance that is formed is creation.
if the matter changed from one substance to another this is called a chemical reaction.
Surely not. It won't change the molecular level.
Hope that helps.
3
1. The observed regularities in the properties of
the elements are periodic functions of their
(1) atomic numbers
(2) mass numbers
(3) oxidation states
(4) nonvalence electrons
Answer:
(1) atomic numbers
Explanation:
The observed regularities in the properties of the elements on the periodic table are periodic functions of their atomic numbers.
Atomic number is the number of protons in an atom. The periodic law states that "the properties of elements are a periodic function of their atomic number".Elements on the periodic table are arranged based on the atomic numbers they contain. The number of positively charged particles in an atom is the atomic number.The observed regularities in the properties of the elements are periodic functions of their atomic numbers.
Modern periodic law states that "Properties of elements are a periodic function of their atomic number not by their atomic mass". Modern periodic law was proposed by Henry Moseley in 1913. Physical and chemical properties of elements depend on the number of electrons and their arrangement.
Thus properties of elements are periodic function of their atomic numbers and not atomic masses. If the properties of an element depend on number of proton and neutron then the properties are periodic function of their atomic mass so we can conclude that the observed regularities in the properties of the elements are periodic functions of their atomic numbers.
Learn more: https://brainly.com/question/19534915
Describe the ammonium ion, NH4+, and the sulfate ion, SO42-. What compounds would these ions form with potassium and fluoride ions? Write the formula units for the resulting compounds.
Explanation:
Ammonium Fluoride and Potassium Sulphate
Which of the following best describes an Arrhenius acid-base reaction?
Answer:
A. Acid + base = salt + water
Explanation:
correct for a pex
The correct option is (a) Acid + base = salt + water .
Sweden's Svante Arrhenius proposed the concept of acids and bases in 1884 based on the theory of ionization. According to Arrhenius, acids are hydrogen-containing compounds that release H + ions or protons when dissociated in water, and bases are hydroxide compounds that release OH-ions when dissociated in water. Acid + base = salt + water Neutralisation is a reaction between an acid and an alkali that forms a salt and water. Salts are odourless and have a salty taste, and many are soluble in water. Common examples include sodium chloride, potassium iodide, calcium carbonate and copper sulfate. The pH scale is used to measure acidity and alkalinity.Learn more about Neutralisation here https://brainly.com/question/23008798
#SPJ2
What causes high and low tides?
O A. Variations in salinity and temperature transmit waves across the
ocean.
B. As Earth rotates, the moon's gravity pulls on different parts of the
planet.
C. Ocean water is driven by differences in water density.
D. Underwater disturbances displace large amounts of water.
SUBMIT
Please help!!! I can’t figure it out!
Answer:
The third answer
Explanation:
How much energy would be required to heat 10.0 g of water at 0 degrees C to 100 degrees C,and change it into steam at 100 degrees C
Answer:
Q = 4180 J
Explanation:
Given data:
Mass of water = 10.0 g
Initial temperature = 0°C
Final temperature = 100°C
Heat required = ?
Solution:
Specific heat capacity of water is 4.18 j/g.°C.
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
ΔT = 100°C - 0°C
ΔT = 100°C
Q = 10.0 g ×4.18 j/g.°C × 100°C
Q = 4180 J
Anita was using steel to make rusted sculptures. After building each sculpture, she caused the steel in the sculpture to rust by placing it into a tub filled
with salt water for eight hours. Anita wondered if steel would rust faster submerged in vinegar instead of salt water. To find out, Anita cut ten squares of
steel sheet metal and split them into two equal groups. She put one group of squares into a tub filled with salt water and the other group of squares
into a tub filled with vinegar. Once an hour for eight hours, Anita counted the number of rusted steel squares in each group.
What is the manipulated independent variable in Anita's experiment?
Answer:
The type of liquid in the tub (salt water or vinegar)
Explanation:
The manipulated independent variable in Anita's experiment is the type of liquid in the tub.
The independent variable is the controlled or manipulated variable in the course of an experiment. It can also be referred to as the 'cause' variable which has the capacity to produce 'effects' on another variable - the dependent variable.
In this case, the type of liquid the tub is filled (salt water or vinegar) will hypothetically affect the rusting period of the steel. Hence, the dependent variable is the type of liquid the tub is filled while the dependent variable would be the time it takes for the steel to get rusted.
The chemical reaction for photosynthesis is: 6CO2 + 6H2O in sunlight yields C6H12O6 + 6O2. a. What is the function of sunlight in the reaction. b. What is the function of chlorophyll/ chloroplast?
Answer:
Sunlight provide light energy.
Chlorophyll absorb light.
Explanation:
Sunlight provide light energy or give light energy from sun and it is use to produce glucose from carbondioxide and water which is also a source of energy.
Chlorophyll absorbs light energy and use it to convert carbondioxide and water into glucose and oxygen or it captures sun rays and produce glucose and water.
When an aluminum atom becomes an ion, what is its charge?
Answer:
Initially, the aluminum atom had a charge of +13 + (−13) = 0; in other words, its charge was neutral due to the equal numbers of protons and electrons. When it becomes an ion, it loses 3 electrons, leaving behind only 10. Now the charge is +13 + (−10) = +3.
Thank you and please rate me as brainliest as it will help me to level up
Please help any expert be sure your 100% correct please THANK YOU SO MUCH! ANY TEACHER PLEASE HELP!! THIS IS SCIENCE PLEASE EXPLAIN IT TO ME!!!
Would it be possible for electrons in the 2p orbitals to be inside the 2s orbital?
(Please explain)
Answer:
Yes
Explanation:
You can have 2s and have part of the 2p of the row in the p section.
Metal X displaces metal Y. Metal Z does not react with X or Y. What is the correct order of decreasing reactivity for metals X, Y, and Z?
Answer:
Metals on top of the activity series can displace metals at the bottom and they are highly reactive as compared to metals at the bottom of the series.
Hence, the order is X>W>Y>Z.
A teacher showed this animal to students on a field trip which tool will allow the students to best see the animal up close
Answer:
Magnify glass