(đ) is answer of question.
Explanation:
However, the brightness of a star depends on its composition and how far it is from the planet. Astronomers define star brightness in terms of apparent magnitude — how bright the star appears from Earth — and absolute magnitude — how bright the star appears at a standard distance of 32.6 light-years, or 10 parsecs.
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Astronomers measures the luminosity of stars by determining the magnitude of brightness and distance from earth.Thus option C is correct.
What is luminosity?Luminosity of a star is the total amount of energy radiated by them to a distance. The luminosity vary from star to star based on the distance to them.
Luminosity is basically measured in terms of brightness as observed from the earth. Stars will make a group in certain shapes and certain number called constellation. The overall brightness can be then higher for each constellation.
Astronomers define the brightness of stars by the apparent distance from the earth whereas the absolute magnitude is defined is terms of standard distance of 32.6 light years. Hence, the option C based on distance and brightness is correct.
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How many grams of Hydrogen (H) would need to react with 143 grams of Oxygen (O) to make 235 grams of Water (H20)? 235
Answer:
45 grams
Explanation:
what is the empirical formula of a compound that contains only iron and oxygen and is 22.27% oxygen?
Answer:
A) FeO
Explanation:
Options:
A) FeO
B) FeO2
C) Fe2O
D) Fe7O2
The correct answer is A) FeO.
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The empirical formula of a compound that contains only iron and oxygen and is 22.27% oxygen is FeO. The correct option is A.
What is the empirical formula?The simplest whole number ratio of atoms in a chemical molecule is its empirical formula. The empirical formula is the chemical formula that gives the number of atoms of the chemical formula that is given in the chemical reaction.
For example, the C₆H₁₂O₆ is the formula of glucose. The simplest formula is CH₂O. This will be the simplest ratio of this compound. The first one, this C₆H₁₂O₆ is the molecular formula.
It only contains the element one quantity. The empirical formula that contains oxygen and iron will be FeO. The empirical formulas is calculated by dividing the simplest formula.
Thus, the correct option is A) FeO.
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The question is incomplete. Your most probably complete question is given below:
A) FeO
B) FeO2
C) Fe2O
D) Fe7O2
Which law specifically combines volume, pressure, and temperature only?
Charles's Law
Gay-Lussac's Law
Combined Gas Law
Ideal Gas Law
Answer:
Boyles law
Explanation:
I think that is combined gas law.
How many moles of ions are there in 1 mole of iron (III) oxide, Fe2O3?
Answer:
So one mole of Fe2O3 contains two moles of Fe3+ ions.
Explanation:
As there is an internal mole ratio of 2:3
It means that there are 2moles of iron within every mole of iron(III) oxide.
Iron III oxide is an ionic compound composed of Fe3+ ions and O2- ions. According to the formula, there are three O2- ions for every two Fe3+ ions.
Extra:
One 'unit' of Fe2O3 has two Fe3+ ions and three O2- ions, hence a dozen Fe2O3 contains two dozen Fe3+ ions and three dozen O2- ions, and a mole Fe2O3 contains two moles Fe3+ ions and three moles O2- ions.
Building Vocabulary
Match each term with its definition by writing the letter of the correct definition on
the line beside the term in the left column.
5. nucleus
6. proton
D
7. neutron
c.
8. electron
9. atomic number
10. isotopes
a. the sum of protons and neutrons in the nucleus of an
atom
b. the very small center core of an atom
atoms of the same element that differ in the number
of neutrons, but have the same number of protons
d. the particle of an atom that moves rapidly in the
space outside the nucleus
a specific amount of energy related to the movement
of electrons in atoms
f. the particle of an atom with a positive charge
g. the number of protons in the nucleus of every atom
of an element
h. the particle of an atom that is neutral
11. mass number
e.
12. energy level
a
Answer:
Explanation:
Building Vocabulary
Match each term with its definition by writing the letter of the correct definition on
the line beside the term in the left column.
5. nucleus b
6. proton f
7. neutron h
8. electron d
9. atomic number g
10. isotopes c
11. mass number a
12. energy level e
a. the sum of protons and neutrons in the nucleus of an
atom
b. the very small center core of an atom
c. atoms of the same element that differ in the number
of neutrons, but have the same number of protons
d. the particle of an atom that moves rapidly in the
space outside the nucleus
e. a specific amount of energy related to the movement
of electrons in atoms
f. the particle of an atom with a positive charge
g. the number of protons in the nucleus of every atom
of an element
h. the particle of an atom that is neutral
-. mass number a.
12. energy level e
how does the advancement of medical technology increase the number of medical ethical issues that arise?
Answer:
People are getting richer and richer as technology advances, this may make it so that some people are getting treated unfairly. Signs of little money may support the reason that you are not getting the help you need; this means that health problems would arise more, resulting in an unfair lifestyle.
o Neutralization reactions are a type of__________
reactions.
• The removal of hydrogen ions and hydroxide ions from solution as they form________
causes the pH of the mixture to_________.
If the right amounts of acid and base react, the
resulting solution will be________
Answer:
nala
simba
Explanation:
Which sequence is used to separate a soluble salt from a mixture of a soluble and an insoluble
salt?
A
add solvent, heat the mixture, crystallise the mixture
add solvent, heat the mixture, filter, crystallise the filtrate
B
C
heat the mixture, filter, crystallise the filtrate
heat the mixture, filter, add solvent, crystallise the filtrate
D
(02.01 MC)
Observe the image. What observable property can be used to separate a mixture of sand and rice using this tool? (2 points)
Public Domain
Oa
Color
Ob
Magnetic attraction
oc
Particle size
Od
Texture
8.69 Mostly cl
Answer:
C. Particle size
Explanation:
The sand, which has smaller particles, will go through the sieve, while the rice (with a larger particle size) will not
Which of the following is the best definition of a chemical change?
A. All of these
B. The ability of something to undergo a change or reaction.
C. Something that can be observed or measured without changing the identity of the substance.
D. A change that alters the identity, or chemical composition, of a substance at the atomic level.
Answer:A
Explanation:
what are the important features about earth plates
Deep ocean trenches, volcanoes, island arcs, submarine mountain ranges, and fault lines are examples of features that can form along plate tectonic boundaries.Because of the plates there are many things that is being made with the plates, but without the plates that makes earthquakes there wouldn't be any mountains,volcanoes, islands, fault lines, etc.For example, the San Andreas Fault couldn't have been made if it weren't for the plates.
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Someone pls help me I will make you brain
Answer:
Lung function decreses at a faster rate for young people (last answer choice)
Explanation:
how would the rate of diffusion change if the po2 in the capillaries was 40 mmhg and the po2 in the muscle cell changed from 40 to 20 mmhg?
The rate of diffusion change would increase if the PO₂ in the capillaries was 40 mmHg and the PO₂ in the muscle cell changed from 40 to 20 mmHg.
Simple diffusion is the movement of molecular substances from a region of higher concentration to lower concentration. The mechanism with which the movement of O₂ travels from the blood to the body tissues takes place with the use of simple diffusion.
Now, if PO₂ changes from 40 → 20 mmHg in the muscle cells, and the PO₂ in the blood = 40mmHg. It implies that the pressure gradient(P) has increased. As such, there is an increase in the rate of diffusion of oxygen from the blood to muscle cells.
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What words did the Pilgrims use to describe the new laws?
new and legal
just and equal
godly and fair
In the underlined section, what do the colonists promise to do?
“… and by virtue hereof to enact, constitute and frame such just and equal Laws, … as shall be thought most meet and convenient for the general good of the Colony, unto which we promise all due submission and obedience.”
—Mayflower Compact
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ur answer will be reported if u do
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First State : Punjabsoil - Alluvial soil
crops - Cotton, wheat, sorghum, bajra, maize, barley, jute, tobacco, green and black gram, chickpea, pigeon pea, etc.
Suitable properties : Mix of sandy loam and clay soil. Quick draining in nature. Rich in humus (organic matter) and phosphoric acid
Second state : Maharashtrasoil - black soil
Crops - Cotton is the major crop. Other crops include wheat, cereals, rice, jowar, sugarcane, linseed,
Suitable properties : Black soils get sticky when fully wet. Rich in magnesium, iron, aluminum, and lime. They moisture excellently.
Third state : Orrisasoil - laterite soil
crops - wheat, rice, pulses, rubber, tea, coffee, coconut, and cashews.
suitable properties : These Soils are acidic in nature and coarse and crumbly in texture. it is also rich in iron content.
Fourth state : Rajasthansoil - Arid soil
crops - Barley, maize, wheat, millets, cotton, and pulses.
Suitable properties - Sandy soils with low clay content, Saline in nature. Rich in plant food. Poor in organic matter and moisture because arid regions are usually dry.
Fifth state : Sikkimsoil - Mountain and Forest Soil
Crops- Wheat, barley, maize, tea, coffee, spices, tropical and temperate fruits.
Suitable properties - Acidic soil, rich in organic matter. Poor in lime, phosphorus, and potash. Good fertilization is required in these soils.
Which statement best describes a physical change?
1 Changes can occur to certain chemical properties of the substance, but the overall shape of the substance will remain the same.
2 Changes can occur to certain physical properties of the substance, but the overall shape of the substance will remain the same.
3 Changes can occur to physical properties of a substance, but the chemical composition of the substance remains the same.
4 Changes can occur to chemical properties of a substance, but the chemical composition of the substance remains the same.
Answer: 3 Changes can occur to physical properties of a substance, but the chemical composition of the substance remains the same
Explanation:
Physical change mainly physical properties of a substance while the chemical changes remain unchanged. Once there is a change to the chemistry of the substance, this would be classified as a chemical change.
Coffee has a pH of about 5. Therefore, coffee is -
Question 6 options:
neutral
extremely acidic
somewhat acidic
basic
Answer:
The answer to your question is Basic
Explanation:
pH ranges from 0 to 14, with 7 being neutral. pHs less than 7 are acidic while pHs greater than 7 are alkaline (basic).
I hope this helps!
Someone pls help me I will make you brain
Answer:
i cant read it but its c and a
Explanation:
my thinking faces
Someone pls help me I will make you brain
The phenomenon is known as the Greenhouse Effect.
When the sun's energy reaches the Earth, some is reflected into space, but the rest is absorbed by gases and warms the atmosphere. The phenomenon is known as the Greenhouse Effect.
isotopes Mg-24,Mg-25 and Mg-26 has natural abundance of 79.0%,10.0% and 11.0%. Calculate the relative atomic mass for isotopes Mg-24,Mg-25 and Mg-26.
Please help me with with this question....
PlEASE HELP MEEEE ASAP 50 PTS
When potassium metal is placed in water, a large amount of energy is released as potassium hydroxide and hydrogen gas are produced in the reaction 2K(s) + 2H20m - 2KOH(aq) + H2(g)- Your lab partner says this is a redox reaction and a combustion reaction. Do you agree? Defend your answer by explaining whether or not it meets the requirements of each type of reaction.
Yes,I agree that it is a redox reaction.
In the given reaction potassium metal is placed in water and when a reactive metal is placed in water, it reacts with water to form metal hydroxide and hydrogen gas, as a result, potassium hydroxide and hydrogen gas are produced in the reaction.
A redox reaction is a reaction in which a substance is oxidized during the reaction whereas some other substance is reduced during the reaction, simultaneously.
The given chemical reaction is:
2K(s) + 2H20(l) arrow 2KOH(aq) + H2(g)
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Answer:
In the given reaction potassium metal is placed in water and when a reactive metal is placed in water, it reacts with water to form metal hydroxide and hydrogen gas, as a result, potassium hydroxide and hydrogen gas are produced in the reaction.
Explanation:
why don't electrons, which are attracted to the protons in the nucleus, simply fall into the nucleus?
Answer:
electrons are fermions, they can only access an energy level if it has not already been occupied by another electron. Thanks to this principle, there is a minimum energy level within the atom and it is not possible for an electron to collapse to the nucleus because it cannot exceed this} threshold.
Explanation:
I hope I have helped you.
Occurs between a metal atom and a nonmetal atom.
Options:
Ionic Bond or Covalent Bond?
write the 5 major characteristics of traditional map making
Answer:
insta
Explanation:
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what is the condensed electron configuration for nitrogen
Answer:
In writing the electron configuration for nitrogen the first two electrons will go in the 1s orbital. Since 1s can only hold two electrons the next 2 electrons for N goes in the 2s orbital. The remaining three electrons will go in the 2p orbital. Therefore the N electron configuration will be 1s22s22p3.
Explanation:
hope you get it right:)
Answer:
the electron configuration for N will be 1s^2 2s^2 2p^3
Which option correctly describes the pattern of reactivity and electronegativity in nonmetals?(1 point)
Both reactivity and electronegativity decrease down a group.
Reactivity decreases down a group, and electronegativity increases down a group.
Both reactivity and electronegativity decrease up a group.
Reactivity increases down a group, and electronegativity decreases down a group.
Answer:A, Both reactivity and electronegativity decrease down a group.
Explanation: As you go down the periodic table they both will decrease
A fictitious element X is composed of 10.0 percent of the isotope 55 X, 20.0 percent of the
isotope 56 X, and 70.0 percent of the isotope 57 X. Estimate the atomic mass of element X.
Answer:
56.6 g/mol.
Explanation:
Assuming here that we have 100 atoms of each element. The percentage tells us that we have 10 atoms of the 55 isotope, 20 of the 56, and 70 of the 57.
So the total is 10*55 + 20*56 + 70*57 = 5,660. And to get the average, we just divide by the total number of atoms (100).
Atomic mass = 5660/100 = 56.6
What happens in the following cases. [ ( write two eg for each also write is there any ex
change of energy ) ] i) when an element combine with another element. ii) When an element combine with a compound. iii) When a compound combine with another compound.
mjhhhhhhhhhhmmmmnnñbb
The speed of light is 300,000,000 m/s. What is the frequency of a wave with a wavelength of 6 meters?
Answer:
50,000,000 Hz
Explanation:
Rearrange the formula:
wave speed = frequency × wavelength → frequency = wave speed ÷ wavelength
wave speed = 300,000,000m/s
wavelength = 6m
Substitute in the values:
frequency = 300,000,000 ÷ 6
frequency = 50,000,000 Hz
Hope this helps!
Look at the image shown.
Two H are written with a horizontal straight line between them. (H-H)
What does this image represent?
Linear molecule with one domain
Linear molecule with two domains
Tetrahedral molecule with four domains
Trigonal planar molecule with three domains
Explanation:
It is known that an electron pair represents a domain. Hybridization of BF_{3}BF3 will be calculated as follows.
Hybridization = \frac{1}{2}[\text{Valence electrons of central atom + no. of bonded atoms + negative charge - positive charge}]21[Valence electrons of central atom + no. of bonded atoms + negative charge - positive charge]
Valence electrons of boron are 3 and no. of bonded atoms in a BF_{3}BF3 molecule is 3.
Therefore, calculate hybridization of BF_{3}BF3 as follows.
Hybridization = \frac{1}{2}[\text{Valence electrons of central atom + no. of bonded atoms + negative charge - positive charge}]21[Valence electrons of central atom + no. of bonded atoms + negative charge - positive charge]
= \frac{1}{2}[3 + 3 + 0]21[3+3+0]
= 3
Hence, hybridization of BF_{3}BF3 is sp^{2}sp2 , that is, trigonal planar.
Thus, we can conclude that the given image represents that it is a trigonal planar molecule with three domains.
Answer:
electron pair => 1 covalent bond => same as H:H
Explanation:
The bar notation is generally accepted as a pair of electrons depicting a 'single' chemical bond. If two bars are shown (e.g; C=C) then two chemical bonds are represented. If three bars are shown (e.g; N≡N) then three chemical bonds are represented. This is the highest number of bonds that can exist between two elements. Hope this helps. :-)