Answer:
-20.2 * 10^-18 J
Explanation:
From;
E = hc/λ
h= planks constant = 6.6 * 10^-34 Js
c= speed of light = 3 * 10^8 ms-1
λ = wavelength = 10.8 * 10^-9 m
Substituting values;
E = 6.6 * 10^-34 * 3 * 10^8/ 10.8 * 10^-9
ΔE = -1.8 * 10^-17 J
But for ground state E1=−13.6eV or -2.176 * 10^-18 J
From;
ΔE = E4 - E1
E4 = ΔE + E1
E4 = (-1.8 * 10^-17) + (-2. 176* 10^-18)
E4 = -20.2 * 10^-18 J
How are elliptical galaxies different from spiral galaxies?
a. They contain older stars and less gas and dust.
b. They contain younger stars and more gas and dust.
c. They are bigger than spiral galaxies.
d. They are smaller than spiral galaxies.
Answer:
A. They contain older stars and less gas and dust.
Explanation:
There are three types of galaxies:
elliptical galaxiesspiral galaxieslenticular galaxiesElliptical galaxies are galaxies shaped like an ellipse, while spiral galaxies consist of a flat, rotating disk that contains stars, gas, and dust, and a central concentration of stars called the bulge.
The difference between elliptical and spiral galaxies is in the amount of gas and dust they contain. Spiral galaxies contain large amounts of gas and dust, which means that new stars are born very often. This makes them brighter than relatively dim elliptical galaxies, which contain less gas and dust. This is why fewer new and brighter stars are born in elliptical galaxies, leaving them with older, dimmer stars.
Determine the possible traits of the calves if:
A red bull (RR) is mated to a red (RR) cow 1
Answer:
A red (RR) bullis mated with white (WW) cow 1
Answer:
A roan (RW) is mated with red(RR)cow 3
Answer:
Answer:
1. All red calves i.e. RR
2. All roan calves i.e RW
3. 2 red calves (RR) and two roan calves (RW)
Explanation:
According to this question, a gene coding for fur colour in cattle is involved. Red alleles (R) and white alleles (W) are co-dominant to produce a roan cattle (RW). The possible traits of the following crosses are (see attached punnet square):
1) A red bull (RR) is mated to a red (RR) cow: All red calves i.e. RR
2) A red (RR) bullis mated with white (WW) cow: All roan calves i.e RW
3) A roan bull (RW) is mated with red (RR) cow: 2 red calves (RR) and two roan calves (RW).
The diagram below shows an oxygen molecule formed when two oxygen atoms bond. Which is likely to be the nature of bonding formed?
Answer:
Covalent bonding
Explanation:
covalent bonding
What is the half life of an atom that goes from 16000 g to 125 g in 163.24 days.
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].
Barry purchased a whole life insurance policy. Which of the following choices is true?
Answer:
where the following choices??
Explanation:
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
How many atoms are in 1.65 mol of potassium
Answer:
9.93 × 10²³ atomsExplanation:
The number of atoms of potassium can be found by using the formula
N = n × Lwhere n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
From the question we have
N = 1.65 × 6.02 × 10²³
We have the final answer as
9.93 × 10²³ atomsHope this helps you
HELP PLEASE ANSWER ASAP!!!!!
When atoms react, they often lose, gain, or share electrons to form a more stable version of themselves. For example, alkali metals such as sodium (Na) lose their outer shell electron in their reactions to form compounds. The electron configuration of alkali metals would then resemble those of which group of the periodic table in the compounds they form?
a. 7A or group 17
b. 8A or group 18
c. 2A or group 2
d. 1A or group 1
Answer:
D
Explanation:
Suzanne has a cat and uses a pet carrier to take her cat to the veterinarian. After a few years, the cat runs away and hides every time Suzanne gets the carrier out. Which best describes the cat's behavior? instinct reflex conditioned imprinting
Answer:
conditioned
Explanation:
The best term to describe the behavior of the cat is conditioned.
The cat has been conditioned to respond in a specific way to the pet carrier over time due to certain experiences - most likely, unpleasant ones. With repeated unpleasant experience associated with the per carrier, the cat has been conditioned to dislike/fear the pet carrier and thus, the recorded behavior.
Answer:
conditioned
Explanation:
How many valence electrons are in Lithium
Answer:
Por ejemplo, el Litio se ubica en el grupo 1A, entonces tiene 1 electrón de valencia.
Explanation
Excepto los grupos 3-12 (los metales de transición), el dígito de las unidades del número de grupo identifica cuántos electrones de valencia se pueden asociar con un átomo neutro de un elemento listado en dicha columna.E
8. An atom of element Z has the
electronic configuration 2.8.6. Which
one of the following statements
about element Z is correct? *
Answer:
See explanation
Explanation:
The question is incomplete but i will try to answer it to the best of my ability.
An element of configuration 2.8.6 is in group 16. This element will form a divalent anion Z^2-
Z is a nonmetal which combines with metals to form ionic bonds. Z can also react with other non metals to form covalent compounds.
Z is expected to have high electronegativity and electron affinity since it is a nonmetal of group 16.
The oxides of Z will dissolve in water to yield acidic solutions.
Question 12 of 25
Which sentence describes all atoms of one element?
O A. They have the same number of protons.
OB. They have the same number of neutrons.
O C. They have the same number of isotopes.
D. They have the same properties.
Answer:
D They have the same properties.
Explanation:
The same no. of isotopes doesnot describes because isotopes have same symbol but didderent atomic mass.
Which option will increase the rate of reaction?
A) removal of one of the reactants
B) decrease the volume of container
C) lower the temperature of reaction
D) reduce the pressure in the container
Answer:
B
Explanation:
when you increase the pressure of a closed container , its volume decreased.
in general when pressure is increased, rate of reaction is increased.
Being farther from the nucleus and with more electrons shielding the protons results in the valence electrons being held ...
Answer:
electrons
Explanation:
since they are at the outer part of nucleus
Answer:
Weakly
Explanation:
Being farther from the nucleus and with more electrons shielding the protons results in the valence electrons being held weakly.
The effect of the nuclear pull will not be felt so strongly by the valence electrons. The valence electrons are the outermost electrons that occupies a shell. When the inner orbital electrons are much and the atomic radius is large, the valence electrons are well shielded. This results in electropositivity and a low ionization energy.Which of the following causes a physical change in the shape of an object?
A. Using a wire to conduct electricity
B. Heating a piece of iron until it glows
C. Placing a penny in acid to make it shiny
D. Sharpening the tip of a pencil
please helppp
Answer:
B
Explanation:
Heating a piece of iron until it glows.
Heating a piece of iron until it glows causes a physical change in the shape of an object. Therefore, option B is correct.
What is physical change ?The term physical change is define as a type of change where the physical properties of matter change. In physical change, composition and chemical nature of matter does not change.
It involves in change in physical properties. The examples of physical changes are textural change, shape, size, color, volume and density.
Heating a piece of iron until it glows causes a physical change in the shape of an object, because it involves physical property. The changes in which only physical properties of substances are changed, and no new substance is formed
Thus, option B is correct.
To learn more about the physical change, follow the link;
https://brainly.com/question/3680148
#SPJ2
PLEASE HELP! THIS A TIMED QUIZ!!
Scientists found an artifact that has 25% of Carbon-14 left. Based on how much Carbon-14 is remaining, how old is the artifact that was found?
A). 17,100 years
B). 5,700 years
C). 22,800 years
D). 11,400 years
Answer: D
Explanation:
For an atom of chlorine-35, what number would you put as the SUPERSCRIPT in the atomic notation?
simply parmanent tissue real life application please help it's for my project
A 1.5 m block of tungsten has a mass of 28 875 kg.
Write down the equation that links density, mass and volume.
Explanation:
Density is an intensive property of any matter. Any given pure sample of a substance will have the same density value.
Density is the mass per unit volume of a compound;
Mathematically;
D = [tex]\frac{M}{V}[/tex]
where M is the mass
V is the volume
D is the density
A physical change is when the atoms combine to create a new product.
>True
>False
What sport was used to demonstrate Newton's 3 Laws?
Compression is the type of stress that deforms rock at which location ?
Answer:
Compression is common at convergent boundaries, tension in divergent boundaries, and shear at transform boundaries.
Explanation:
The three main types of stress go along with the three types of plate boundaries. Rocks can bend and fold. Rocks can also fracture and break.
help me please I really need it
a) Magnesium, 2.8.2, Group number 2,Metals, They are not non metals.
b) Fluorine, 2.2.5, Group number7, Metal No, Non-Metal yes
c) Carbon, 2,2,2. Group number 4, Metal No, Non-Metal yes
_____________________________________Best Regards,'Borz'What type of ions do nonmetals naturally form?
Answer:
Negative Ions
Explanation:
Nonmetals naturally form Negative Ions by gaining electrons to fill the valence shell
How many neutrons are in the nucleus of an atom with a mass number of 80 and an atomic number of 35?
Answer: 45
Explanation:
mass number = number of protons and neutrons
atomic number = number of protons
to find neutrons subtract atomic number from mass number
so 80 - 35 = 45 neutrons
A student needs to use sodium nitride in an experiment and finds a chemical with the formula NaNO3 . Is this the correct compound? Why or why not?
A. Yes, NaNO3 is the formula for sodium nitride.
B. No, NaN is the formula for sodium nitride; NaNO3 is the formula for sodium nitrate.
C. No, NaN is the formula for sodium nitride; NaNO3 is the formula sodium nitrite.
D. No, Na3N is the formula for sodium nitride; NaNO3 is the formula for sodium nitrat
Answer:
Yes, NaNO3 is the formula for sodium nitride.
Which element would have chemical reactions most similar to fluorine (F)?
A. O
B. Br
C. Ne
D. Fm
giving brainliest if right
[tex]\mathrm {Hey, there!}[/tex]
The answer is: Bromine
Oxygen is not similar to flourine, it is not a noble gas with high ionization.
Neon does not have chemical reactions like flourine.
The answer is Bromine! Best of Luck!
Answer:
Br
Explanation:
HELPP!!! ASAP!!!! BRAINLIEST!!!
Complete the following sentences. Energy is required to _______ bonds in a molecule and released when bonds are _______.
Answer:
Energy is required to break bonds in a molecule and released when bonds are made.
Explanation:
Energy is added to break bonds and released when making bonds.
Which of the following laboratory procedures best illustrates the law of conservation of mass? (Assume the product of the reaction includes the mass of any unused reactants.) (3 points)
Reacting 12 g of C with 32 g of O2 to form 44 g of CO2
Weighing 100 g of Cu powder and 100 g of Fe filings
Heating 100 g of CaCO3 to produce 56 g of CaO
Dissolving 10 g of NaCl in 100 g of water
Answer: Reacting 12 g of C with 32 g of O2 to form 44 g of CO2
Explanation: I took the test just now, and the law of conservation of mass means to energy and that is exactly what they do in this answer!
Answer:
A
Explanation:
10. calcium fluoride ca
11. sodium nitride
12. magnesium chloride
In formulas
Answer:
10=CaF2
11=Na3N
12=MgCl2
Explanation:
Answer:
10. CaF2
11. Na3N
12. MgCl2
Explanation: