Answer:
the pair of isotopes are b and e
the element with mass no of 19 is C
the element with atomic no 7is D
Explanation:
B and E are isotopes bcos they have the same atomic no, i.e no of protons. They bother have atomic no of 17 BUT have different mass no i.e sum of neutrons and protons.
(b)C is correct because the sum of the protons and neutrons is 19
(c) D because it has 7 protons
how many different sublevels are in the second energy level?
2
1
4
3
Answer:
The answer is 2
Explanation:
There are two energy sublevels in the second principal energy level. These two energy sublevels are 2s and 2p. The energy distribution in an atom is divided into a number of principal energy levels, and the principal energy levels are again divided into four basic energy sublevels.
18- The number of orbitals in each sublevel are:
A:-s:2, p:3, d:10, and f:14
B:-s:2, p:6, d:10, and f:14
C:-s:1, p:3, d:5, and f:7
D:-s:1, p:2, d:3, and f: 4
s2,p6,d10,f14
S contains 2 orbitals
P contains 6 orbitals
D contains 10 orbitals
F contains 14 orbitals
H2SO4 +HI → __ H2S+12 +H2O balance the equation
Answer:
H2SO4 + 8HI → H2S + 4I2 + 4H2O
What is the wavelength of light with 4.01 x 10^-19 J of energy? (The speed of light in a vacuum is 3.00 x 10^8 m/s, and Planck's constant is 6.626 x 10^-34 Jos.)
A. 1820 nm
B. 496 nm
C. 202 nm
D. 551 nm
Answer:
D
hope it helps:)))!!!!!!
The concept Planck's quantum theory of radiation is used here to determine the wavelength of the light. The wavelength of the light with 4.01 x 10⁻¹⁹ J of energy is 496 nm . The correct option is B.
What is Planck's quantum theory?According to Planck's quantum theory, different atoms and molecules can emit or absorb energy in discrete amount only. The smallest amount of energy which can be emitted or absorbed in the form of electromagnetic radiation is called quantum.
The energy of the radiation absorbed or emitted is directly proportional to the frequency of the radiation. It is given by the equation:
E = hν
ν = E / h
4.01 x 10⁻¹⁹ J / 6.626 x 10⁻³⁴ = 6.05 × 10¹⁴ Hz
We have,
ν = c / λ
λ = c / ν
3.00 x 10⁸ / 6.05 × 10¹⁴ = 4.958 × 10⁻⁷ m
1 nm = 1 × 10⁻⁹ m
4.958 × 10⁻⁷ m = 495.8 nm = 496 nm
Thus the correct option is B.
To know more about wavelength, visit;
https://brainly.com/question/30171018
#SPJ7
What point A on the phase diagram called?
liquid
(374°C/218 atm)
A
solid
pressure (atm)
gas
temperature (°C)
OA.
the melting point
OB.
the boiling point
Ос.
the freezing point
OD
the critical point
OE.
the triple point
Answer:
D) the critical point
Explanation:
Point A is the critical point in phase diagram. This is the highest temperature and pressure at which a pure material can exist in vapor/liquid equilibrium. Pretty cool!
The temperature of a sample of liquid water changes from 50°C to 30°C. Which statement best explains the change
that must happen at the molecular level?
The molecules move more quickly and their average kinetic energy increases
The molecules move more bowly and their average kinetic energy decreases
The molecules move more quickly and their average kinetic energy decreases
The molecules move more slowly and their average kinetic energy increases.
Answer:
The molecules move slower than the temp of 50°c and their average kinetic energy decreases.
Explanation:
kinetic energy cannot increase as temperature is reduced. molecules will still move with reduced motion.
Help, quick, pls
What is a displacement reaction?
[tex]\begin{aligned} -5x+4y &= 3\\\\ x&=2y-15 \end{aligned}[/tex]
Which of the following would be expected to have the highest viscosity? CH3CH2OH, HOCH2OH, CH3CH2CH3
О НОСН2ОН
O They are all the same.
О СН3СН2ОН
O CH3CH2CH3
Answer: Out of the given options [tex]HOCH_{2}OH[/tex] is expected to have the highest viscosity.
Explanation:
The resistance occurred in the flow of a liquid substance is called viscosity.
More stronger is the intermolecular forces present in a substance more will be its resistance in its flow. Hence, more will be its viscosity.
For example, [tex]HOCH_{2}OH[/tex] has strong intermolecular hydrogen bonding than the one's present in [tex]CH_{3}CH_{2}OH[/tex] and [tex]CH_{3}CH_{2}CH_{3}[/tex]. This is because two-OH groups are present over here.
Thus, we can conclude that out of the given options [tex]HOCH_{2}OH[/tex] is expected to have the highest viscosity.
Are your knees the elbows of your legs or are your elbows the knees of your
arms?
A.knees are elbows of your legs
B.elbows are knees of your arms
C.both
Answer:
Both :)
Explanation:
Knees and elbows are the types of joints that are present to move the parts of the body attached to it. The knees are the elbows, and the elbows are the knees.
What are joints?The joints knees and elbows work like the door and allow the movement of the attached body parts in back and forth directions.
The elbow of the arm region and the knee of the leg region have similar functions and are homologous in the function that moves the leg of the lower region and the arm of the upper region.
Therefore, option c. both is the correct option.
Learn more about knee and elbow here:
https://brainly.com/question/27056104
For the reaction C + 2H2 → CH4, how many moles of hydrogen are needed to make 192.3 grams of methane, CH4?
Answer:
24
Explanation:
⬆️= you need to come up with investigation question, to help inform your decision.
Think about how land, water, and air absorb and release
Thermal energy and then formulate your hypothesis
I need some Investigation questions about how land, water, and air absorb and release
Thermal energy :,)
Subject: science
Answer:
1. how dense is the land and what matreal
2. what is the humidity and is there any wind
3.how pure is the water if it full of minarils
Explanation:
can someone please explain core and valence electrons in periods for me please
Answer:
The electrons of an atom are typically divided into two categories: valence and core electrons. Valence electrons occupy the outermost shell or highest energy level of an atom while core electrons are those occupying the innermost shell or lowest energy levels
Explanation:
i hope u get it :))
Draw the structure formula of 2methylbutanoate
Answer:
[tex]CH _{3}CH(CH _{3})CH _{2}COO {}^{ - } \\ \\ [/tex]
State the method you will use to separate the following substances. (a) calcium carbonate from table salt (b) iodine from sodium chloride (c) table salt from seawater (d) sugar from sugar solution (e) pure water from sewage water (f) ethanol from beer (g) yellow dye from durian ice cream
Answer:
https://www.meritnation.com :)I HOPE IT'S HELP
Answer: There are many forms of table salt: coarse salt, refined salt, iodized salt. It is a crystalline solid, white to very pale pink or gray in color, obtained from seawater or salt deposits. Salt obtained from seawater has crystals that are smaller or larger than rock salt. In nature, table salt consists mainly of sodium chloride (NaCl), but also a few other minerals (trace minerals). Table salt obtained from rock salt may appear more gray because of traces of trace minerals. Table salt is necessary for the survival of all living organisms, including humans. Table salt is involved in regulating the body's water content (liquid balance).
what are the compounds for the chemical formula B4S
Answer:
boron sulfide
b=boron
s=sulfer
Explanation:
How many oxygen atoms are in the products of the balanced reaction below?
3Ca + 2AIPO4 + 2Al + Ca3(PO4)2
A. 12
B. 8
C. 3
D. 4
Answer:
B
Explanation:
production ca3(PO4)2
4x2=8
El Niño begins with which of the following?
Answer:
El Niño is a climate cycle in the Pacific Ocean with a global impact on weather patterns. The cycle begins when warm water in the western tropical Pacific Ocean shifts eastward along the equator toward the coast of South America. Normally, these warm water pools near Indonesia and the Philippines.
Explanation:
Read the following reactions. Reaction 1: CaO(s) + CO2(g) → CaCO3(s) Reaction 2: H2O(g) → H2O(l) Which reaction leads to an increase in entropy? Only Reaction 1 Only Reaction 2 Both Reaction 1 and 2 Neither Reaction 1 nor 2
Answer: In the given reactions neither reaction 1 nor 2 reaction leads to an increase in entropy.
Explanation:
The degree of randomness present in the molecules of a substance is called entropy.
In gases, molecules are held by weak forces due to which they move apart from each other. Hence, they have high entropy.
In liquids, molecules are a little close to each other so they have less entropy than gases.
In solids, molecules are tightly held together so they have least or negligible entropy.
As reaction 1 is [tex]CaO(s) + CO_{2}(g) \rightarrow CaCO_{3}(s)[/tex] and it shows that product is in solid state. Therefore, entropy is decreasing.
As reaction 2 is [tex]H_{2}O(g) \rightarrow H_{2}O(l)[/tex] and it shows that gas is converted into liquid. Therefore, entropy is also decreasing here.
Thus, we can conclude that in the given reactions neither reaction 1 nor 2 reaction leads to an increase in entropy.
Answer: Neither Reaction 1 nor 2
Explanation:
Which statement best describes wave-particle duality as it applies to electrons?
A. The electrons present in radio waves and microwaves act more like particles than waves.
B. Electrons are particles that emit waves of radiation when they move from higher energy levels to lower energy levels.
с.Electron clouds can be understood as clumps of particles held near one another by wave forces.
D.Electrons can be modeled as waves in some situations and as particles in other situations.
Answer:
D es pero que te ayude amigo
Please help me guys to solve this problem!
(a) distance measured with metre rule or tape rule
time measured with stopwatch/ stop clock/ timer
Average speed = total distance / time
(b) (i) decrease in speed
(ii) Change in speed = a * t
4.5 m/s
hope this helps......
chemical symbol for an atom of lithium
Answer:
Li
Explanation:
It's on the periodic table.
sulfur and oxygen can react to form both sulfur dioxide and sulfur trioxide in sulfur dioxide there are 32.06 grams of sulfur and 32 grams of oxygen in sulfur dioxide there are 32.06 grams of sulfur are combined with 48 grams of oxygen
a. what is the ratio of the weights of oxygen that combine with 32.06 g of sulfur ?
b. How do these data illustrate the law of multiple proportions?
Answer:
Explanation:
In sulfur dioxide there are 32.06 grams of sulfur and 32 grams of oxygen .
In sulfur trioxide there are 32.06 grams of sulfur are combined with 48 grams of oxygen.
The ratio of oxygen which reacts with 32.06 gram of sulfur is 32: 48 .
This ratio is equal to 2 : 3.
This is in accordance with law of multiple proportion because , the ratio of mass of oxygen which reacts with constant mass of sulfur is integral ratio . Hence they are in accordance with law of multiple proportions.
Answer:
sulfur and oxygen can react to form both sulfur dioxide and sulfur trioxide in sulfur dioxide there are 32.06 grams of sulfur and 32 grams of oxygen in sulfur dioxide there are 32.06 grams of sulfur are combined with 48 grams of oxygen
a. what is the ratio of the weights of oxygen that combine with 32.06 g of sulfur?
b. How do these data illustrate the law of multiple proportions?
Explanation:
In sulfur dioxide ([tex]SO_2[/tex])
32.06 g of sulfur reacts with 32.0 g of oxygen.
In sulfur trioxide ([tex](SO_3)[/tex] 32.0 g of sulfur reacts with 48.0 g of oxygen.
So, both th ecom[pounds are made from sulfur and oxygen,
But the amount of oxygen reacts with fixed amount of sulfur that is 32.06 g and it is in proportions that is:
32.0 g : 48.0 g
=2:3.
Hence, the ratio of oxygen combines with sulfur is in the ratio of 2:3.
b.
This data illustrates the law of multiple proportions.
Because the oxygen which is combining with fixed amount of sulfur is in proportions.
PLZ HELP!!! QUESTIONS ARE BELOW!!! :D PLZ COMPLETELY ANSWER THE QUESTIONS WITH A GOOD ANSWER :)
Answer: sorry its lagging i hope this help fore 18.. =D
Explanation:
n,s is repeating the cycle of the inside
Answer/Explanation:
18, a,
I believe the n, and s represents North, South, or just the way the arrows are rotating repeatedly.
18, b,
The phenomenon re-occurring shows the alignment of magnetic dipoles with in a magnet, like inside. The arrows show a direction in the line with an external magnetic field in a way that it can produce its own magnetic fields that seem to travel from North to the South.
18, c,
Incorrect. Refrigerator magnets have multiple layers of magnification, they use opposite polarities to stay this way. If he puts the magnet sideways it may stick to the fridge
~ LadyBrain
Pu-238 (Plutonium, 238) decays by α emission to form an atom, which atom is this?
Answer:
Helium atom
Explanation:
For the RTGs flown by the United States, the radioisotope has been some chemical form of plutonium-238 (238Pu or Pu-238). Plutonium-238 decays primarily by the emission of an alpha particle (a helium atom without its electrons).
Can you give me a paragraph about the digestive system?
Answer:
The digestive system is very important to animal health. Without the digestive system earth might still be lifeless other than bacteria and what not. The digestive system is a system to keep us full and energized. It allows us to chew and swallow our food and let it break down in our belly acid. Then it departs our body through the large, small intestines to then be flushed out to sea.
~ LadyBrain
Explanation:
an organ that is part of the
digestive system his digestive system is extremely simple
Select the correct answer.
Which atom or lon is the largest?
Answer:urenium
Explanation: because his atomic number is 235
Answer:
We know when the no of protons (+ charge) is greater than the no of electrons (- charge), the nucleus pulls the electrons with greater force, hence making the size smaller. Clearly, the cations are smaller than the atoms, this largest atom/ion will be Ca.
K has 19 protons, 19 electrons
K+ has 19 protons, 18 electrons
Ca has 20 protons, 20 electrons
Ca2+ has 20 protons, 18 electrons
Li has 3 protons, 3 electrons
Clearly, the cations are smaller than the atoms, this largest atom/ion will be Ca.
Explanation:
If one of the reactants in a reaction us Na2O, what is known about the products?
Ok here's the deal
the answer is A: The products will contain exactly 2 Na atoms and 1 O atom.
Explanation:
thank me later space-ex kids
Un compuesto orgánico que contenía solo H y C fue quemado en corriente de O2, encontrándose que 0.210 g daban 0.660 g de CO2.La densidad del vapor del compuesto es de 1.87 g/dm3 a 273 °K y 1 atm. ¿Cuál es la fórmula molecular?
Answer:
[tex]C_3H_6[/tex]
Explanation:
¡Hola!
En este caso, basado en la información dada, es posible calcular las moles de carbono en el compuesto al usar la masa molar del CO2 y la siguiente relación molar:
[tex]n_C=0.660gCO_2*\frac{1molCO_2}{44.01gCO_2}*\frac{1molC}{1molCO_2}=0.015molC[/tex]
Ahora, calculamos las moles de hidrógeno restando la masa de carbono de la de la muestra basado en el siguiente factor molar:
[tex]m_{H}=0.210g-0.015molC*12.01gC/molC=0.030molH[/tex]
Entonces la formula empírica del compuesto resulta:
[tex]CH_2[/tex]
Dado que el carbono y el hidrógeno están en una relación 1:2. Ahora bien, calculamos la masa molar del gas considerando la presión, densidad y temperatura del mismo:
[tex]PV=nRT\\\\PV=\frac{m}{MM}RT \\\\MM=\frac{m}{V}\frac{RT}{P}=\frac{dRT}{P}\\\\MM=\frac{1.87g/dm^3*0.08206\frac{atm*L}{mol*K}*273K}{1atm}=41.9g/mol[/tex]
Es decir que la fórmula molecular y la empírica están en una relación de 3, por lo que la fórmula molecular resulta:
[tex]C_3H_6[/tex]
¡Saludos!
Students measuring the mass of a substance record 1.127 g, 1.214 g, 1.304 g, and 1.184 g. Which other measurement of the substance's mass would be most precise?  A. 1.514 g  B. 1.205 g  C. 1.416 g  D. 1.384 g
Answer:1.205g
Explanation:
Calculate the total amount of energy required in calories to convert 50.0 g of ice at 0.00 degrees Celsius to steam at 100. degrees Celsius.
Specific heat capacity of water is 1.00 cal/g OC
Hfusion = 80 cal/g OC and Hvap = 540 cal/g OC
Write the complete equation you will use.
Substitute the values in the equation in step 1.
Report the math answer with 3 sig figs and the correct unit.
Answer: The amount of heat absorbed is [tex]36.0\times 10^3Cal[/tex]
Explanation:
Few processes involved are:
(1): [tex]H_2O (s) (0^oC, 273K) \rightleftharpoons H_2O(l) (0^oC,273K)[/tex]
(2): [tex]H_2O (l) (0^oC, 273K) \rightleftharpoons H_2O(l) (100^oC,373K)[/tex]
(3): [tex]H_2O (l) (100^oC, 373K) \rightleftharpoons H_2O(g) (100^oC,373K)[/tex]
Calculating the heat absorbed for the process having same temperature:
[tex]q=m\times \Delta H_{(f , v)}[/tex] ......(i)
where,
q is the amount of heat absorbed, m is the mass of sample and is the enthalpy of fusion or vaporization
Calculating the heat released for the process having different temperature:
[tex]q=m\times C_{s,l}\times (T_2-T_1)[/tex] ......(ii)
where,
[tex]C_{s,l}[/tex] = specific heat of solid or liquid
[tex]T_2\text{ and }T_1[/tex] are final and initial temperatures respectively
For process 1:We are given:
[tex]m=50.0g\\\Delta H_{fusion}=80Cal/g[/tex]
Putting values in equation (i), we get:
[tex]q_1=50.0g\times 80Cal/g\\\\q_1=4000Cal[/tex]
For process 2:We are given:
[tex]m=50.0g\\C=1.00Cal/g^oC\\T_2=100^oC\\T_1=0^oC[/tex]
Putting values in equation (i), we get:
[tex]q_2=50g\times 1Cal/g^oC\times (100-0)\\\\q_2=5000Cal[/tex]
For process 3:We are given:
[tex]m=50.0g\\\Delta H_{vap}=540Cal/g[/tex]
Putting values in equation (i), we get:
[tex]q_3=50.0g\times 540J/g\\\\q_3=27000Cal[/tex]
Calculating the total amount of heat released:
[tex]Q=q_1+q_2+q_3[/tex]
[tex]Q=[(4000)+(5000)+(27000)]Cal=36000Cal=36.0\times 10^3Cal[/tex]
Hence, the amount of heat absorbed is [tex]36.0\times 10^3Cal[/tex]