Answer:
I think it's lead (pb). Hope this helps.
Answer:
lead
Explanation:
grass → rabbit → fox
Explain why energy is lost by the rabbits in the middle step of this food chain.
Answer:
The rabbit losses energy by great and waste
Explanation:
The grass loses energy by respiration and a rabbit from eating other living organisms but when the fox eats the rabbit no if not little energy is passed to the fox
Which of the following describes a disconfirmed hypothesis?
it has been proven true
it has been poorly written and needs to be reformed
it has been proven false
it is not testable
Define uniform and non-uniform motion.
Answer:
When a body covers equal distances in a straight line, equal intervals of time are called uniform motion
When a body covers unequal distance in equal intervals of time in a straight line is called non-uniform
Answer:
Uniform motion- is motion in which the
velocity does not change.
Non-uniform motion-occurs when the velocity of an object is not
constant : the object speeds up or slows down during its motion, or changes direction.
Hope it will help you !!
Fractions of crude oil
Answer:
Fractions. There are several ways of classifying the useful fractions that are distilled from crude oil. One general way is by dividing into three categories: light, middle, and heavy fractions. Heavier components condense at higher temperatures and are removed at the bottom of the column.
Answer:
Fraction: No. of carbon atoms: Boiling point range oC:
Gasoline (petrol) 4 - 12 32-160oC
Kerosine (paraffin) 11 - 15 160-250oC
Diesel oil 15 - 19 220-350oC
Residue lubricating oil heavy fuel oil bitumen C Above 350oC
Explanation:
Fractions. There are several ways of classifying the useful fractions that are distilled from crude oil. One general way is by dividing into three categories: light, middle, and heavy fractions. Heavier components condense at higher temperatures and are removed at the bottom of the column
If you burn a citronella candle near your picnic will it keep mosquitoes away
Answer:
Thanks!!!
Explanation:
Answer:
true
Explanation:
A student is investigating potential and kinetic energy by stretching a spring across a table
At which step is the potential energy in the spring the greatest
Answer: when it’s fully stretched across the table
Explanation: because when it’s stretched it has the most potential kinetic energy
Marta wants to explain how pollution is affecting the biodiversity of a local lake. Which of the following models are most appropriate options to use in her explanation? I. Graph II. 3-D model III. Simulation
Answer:
Graph models are most appropriate options to explain how pollution is affecting the biodiversity of a local lake.
Explanation:
Marta wants to explain how pollution is affecting the biodiversity of a local lake
For explanation
we have to use the graph because graph only shows the gradual level of of pollution that affect the biodiversity of a lake and water resources.
3D model and simulation is also effective but graph model is is more effective than other
To learn more about pollution refer:
https://brainly.com/question/20782855https://brainly.com/question/121917612.
What is the density of a 625 g cube of metal with a volume of 89 mL?
Answer:
density = 7.02 g/mL
Explanation:
density is mass over volume, just divide
d = 625 g/89 mL = 7.02 g/mL
Define measurement. why is it important in our life?
Answer:
Measurements are so often taken for granted we sometimes do not appreciate the grand importance measurements play in our lives. On a baseline level, measurements fall into the categories of weight, area, volume, length and even temperature. While we look at these various categories as stoic forms of mathematical measurements a closer examination of things we do in everyday life reveals their clear importance.
Explanation:
Measurements provide structure and remove the chaos that would result without any congruent method of understanding weight, mass, temperature, etc.
Answer:
The comparison of unknown physical quantity with the known standard quantity of the same kind is called measurement.
Measurements play an important role in daily life because they are useful to do basic tasks, such as take a child's temperature with a thermometer, make time estimations, measure out medicine and find weights, areas and volumes of different materials or substances.
Hope it helps you.what are fossil fuels?
A fossil fuel is a natural substance formed from the buried remains of ancient organisms that can be used as a source of energy. Fossil fuels formed over millions of years as heat and pressure from layers of sediment changed the decayed organic remains into materials such as coal and petroleum.
How are they made?Fossils fuels are usually made of fossilized plant and animal remains from millions of years ago. The creation of fossil fuels—either oil, natural gas, or coal—from these fossils is determined by the type of fossil, the amount of heat, and the amount of pressure which they bore.
Hope it helps....
(by Benjemin)
Why are intensive properties useful for identifying a substance
Answer:
Intensive properties can be used to help identify a sample because these characteristics do not depend on the amount of sample, nor do they change according to conditions.
name four states of matter
Answer:
1. solid
2. liquid
3. gas
4. plasma
Explanation:
In physics, a state of matter is one of the distinct forms in which matter can exist. Four states of matter are observable in everyday life: solid, liquid, gas, and plasma.
In the circular flow diagram, what do firms provide to product markets?(1 point)
Answer:
Firms produce goods and services,which they sell to households in return for revenue.
Answer: Goods and Services
Explanation:
A photon of 498mm was emitted from a silicon atom. calculate the energy of all the atomic levels of silicon and show that the atomic levels are quantized.
A photon is an elementary particle that has zero invariant mass and travels in a vacuum with a constant velocity. It is capable of generating electromagnetic phenomena since it carries all forms of electromagnetic radiation:
X-rays Ultraviolet light Visible light Gamma rays Infrared light Radio waves Microwaves and radio wavesThe photon presents wave and corpuscular properties, this means that it behaves as a wave in certain phenomena, such as refraction in a lens; and as a particle when it interacts with matter to transfer energy. The latter is expressed as follows:
[tex]E=\frac{hc}{lambda} = hv[/tex]
E is the energy, in physics it is defined as the capacity to do work.h is Planck's constant, a physical constant that plays a role in the theory of quantum mechanics and it is a constant between the energy of a photon and the frequency of its electromagnetic wave ([tex]E = hv[/tex]) Its value is 6.63 x 10^-34 J/s.c is the speed of light, which is 3x10^8 m/s.lambda (λ) is the wavelength, the distance traveled by a periodic disturbance propagating in one cycle. v is the frequency of the wave, it is the inverse of the wavelength, the number of repetitions per unit time of any periodic event.This means that each photon has energy that is proportional to the frequency of light. In this case, the energy is quantized, which means that the energy of the photons is restricted to certain values. The energy at subatomic levels occurs in packets that refer to the photon, which are the packages of energy and each one correspond to different types of radiation.
This differs from classical waves, which can gain or lose arbitrary amounts of energy.
If we apply the equation and replace the information, we have:
[tex]E=\frac{6.63 x 10^{-34} J/s x 3 x 10^{8} m/s }{498 nm} = 3.99 x 10^{-28} J[/tex]
So 3.99 x 10^-28 J is the amount of energy of the photon of 498 nm emmited from a silicon atom.
Now we will show that the atomic levels are quantized. An atom has ground state (n=1) energy of 13.6 eV. Higher states means the atom is at an excited state. When this happens, an electron from an atom loses energy and makes a transition to a lower state. To avoid this and conserve energy, the atom emits a photon with an amount of energy that equals the difference of energy between a ground state and another state. So we can calculate the energy of the electron in different states.
[tex]E_{n} = \frac{-13.6 ev}{n^{2} }[/tex]
[tex]E_{1} = \frac{-13.6 ev}{1^{2} }=-13.6 ev[/tex]
[tex]E_{2} = \frac{-13.6 ev}{2^{2} }=-3.4 ev[/tex]
[tex]E_{3} = \frac{-13.6 ev}{3^{2} }=-1.511 ev[/tex]
N represents the principal quantum number, which is the overall energy of each orbital. This energy increases as its distance from the nucleus increases. Here we can se that the value of energy of n=1 is higher than energy of n=2, and this one is higher from the energy of n=3. This means each level has a specific energy and it is quantized according to the value of n.
So, a photon is an elementary particle which carries radiation and presents a wave-corpuscle duality, where particles may exhibit wave-like behavior in some experiments while appearing as particles in others. A photon is emmited when an atom loses energy, to conserve this energy and avoid a transition to a lower state. The electron energy is quantized because it is restricted to characteristic values, only taking non-continuous values. In this question, the amount of energy of the photon emmited is 3.99 x 10^-28 J. And the atomic levels are quantized according to the principal quantum number.
Learn more about photons here: https://brainly.com/question/18101137
Most Ancient Greek philosophers discusses the world around them but did not do any experiments or make detailed observations
Answer:
Because to them it was just a little bit of fiction. so they don't really think it's necessary to do experiments or make detailed observation
Explanation:
it's just like how we presently today discuss about robot talking to us like humans but it's not yet come to pass .
IF U ANSWER ILL BRAINLIST AND GIVE U 5 STAR PLUS U GET EXTRA POINTS:)) WRITE IT IN UR OWN WORDS PLS OR NO POINTS.
The burning of a magnesium ribbon is an example of a reaction producing a metal oxide.
a) What reactants are required to production of a metal oxide?
b) Write a general equation for the production of a metal oxide.
Answer:
a) When the magnesium metal burns it reacts with oxygen found in the air to form Magnesium Oxide. A compound is a material in which atoms of different elements are bonded to one another. Oxygen and magnesium combine in a chemical reaction to form this compound. After it burns, it forms a white powder of the magnesium oxide.
b) Metals react with oxygen in the air to produce metal oxides. For example, magnesium reacts with oxygen to produce magnesium oxide when it is heated in air: magnesium + oxygen → magnesium oxide 2Mg + O2 → 2MgO
Explanation:
Hope it helps. if yes, plz mark me as brainliest
which of the folowing idead about thr atom changed when new evidence was discoverd
Answer:
Further scientific studies showed that an atom can further be divided into subatomic particles electrons, neutrons, and protons. Thus the idea of the indivisibility of an atom changed when new evidence was discovered.
If you were converting from Milli- to Centi- units, how many decimal places would you move?
Answer:
1 decimal place
Explanation:
centi- is 10 times larger than milli- (centi- = 0.01 milli- = 0.001)
1 mili is equal to the 0.01 centi. Since all metric units differ by powers of ten, changing between them just necessitates moving the decimal point to the left or right.
What is difference between millimeter and centimeter ?The actual ratio is 10 millimeters to 1 centimeter. Now, it is clear that centimeters are bigger than millimeters.
There is no change in volume, these measurements are the same. The main distinction is that fluid quantities are measured in milliliters, but solid quantities are measured in cubic centimeters. 1 cc is 1 mL no matter what is being measured.
The units used to measure length are centimeters and millimeters, respectively. 1 cm is equivalent to 10 mm, and 1 millimeter is equal to 0.1 centimeter.
Thus, for converting from Milli- to Centi- units 10 digit place would be move.
To learn more about millimeter and centimeter refer the link below;
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Frost disappears from the window in the morning
a
Chemical Change
b
Physical Change
Answer:
the answer is b
Explanation:
Physical changes affect a substance's physical properties but do not alter its chemical structure. Types of physical changes include boiling, clouding, dissolution, freezing, freeze-drying, frost, liquefaction, melting, smoke and vaporization.
what happens to concrete after heating it
Why is it impossible for an element to have an atomic number of 110.5? (1 point)
A_ Exactly half of the isotopes would need an atomic number of 110, and half would need an atomic number of 111, which is very unlikely.
B_ Atoms of an element all have the same whole number of protons and neutrons.
C_ Atoms with atomic numbers greater than 100 are unstable.
D_ Atoms of an element all have the same whole number of protons.
Answer:
C
Explanation:
I asked my teacher
The number of protons in an atom are always whole numbers hence it is impossible for an element to have an atomic number of 110.5. The correct answer is option D: Atoms of an element all have the same whole number of protons.
We define the atomic number as the number of protons in an atom. The number of protons in all the atoms of en element must be a whole number.
There is no half proton in the atom hence we can not have an atomic number of 110.5.
Learn more: https://brainly.com/question/8834373
Sugar Dissolving
a
Chemical Change
b
Physical Change
Chemical change cuz you are adding another substance to your water which changes the molecular structure of the water.
as the amount of water decreases in a glass of water you are drinking the desitny of water also decreases true or false
Answer:
False: the density does not change. if the water became more dense, it would move onto the next state of matter, which is ice. the only thing that changes by adding more water is weight
Answer:
False
Explanation:
This is because as the volume decreases the density increases
What is the function of phloem tissue in the plant transport system?
A.it prepares food
B.it transports food
C.it transports water
D.it provides support
Answer:
option B is the right answer it helps in transfer of food.
How many moles of magnesium bromide are formed when 3.0 moles of magnesium reacts with 2.0 moles of bromine?
Mg+Br2 -> MgBr2
Answer:
Explanation:
Hello there, I think this is a limiting agent question.
When 3 moles of Mg is reacted with 2 moles of Br2, because of ratio, we just need 1.5 moles of Br2, so Mg is a limiting agent.
So 3 moles of Mg will make 3 moles of MgBr
Answer:
Use the given functions to set up and simplify
Mg+Br2→MgBr⋅2.
3=
2=
Mg+Br2→gBr⋅2=r2B+gM→MgBr⋅2
Explanation:
SORRY IF I AM WRONG HAVE A BLESS DAY :D
state two application of chemistry on each of the following:-
1.forensic
2.agriculture
3.industrial
4.millitary
5.space science
Explain what is meant by a weak acid
Answer:
A weak acid is an acid which dissociates partially to release few hydrogen protons or ions
Explanation:
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stute 2 lomportance of weather fore castings
Answer:
Climatology and Weather Forecasting is important since it helps determine future climate expectations.Forecasts based on temperature and precipitation are important to agriculture, and therefore to traders within commodity markets. Temperature forecasts are used by utility companies to estimate demand over coming days.Explanation:
Climatology and Weather Forecasting is important since it helps determine future climate expectations. Through the use of latitude, one can determine the likelihood of snow and hail reaching the surface. You can also be able to identify the thermal energy from the sun that is accessible to a region.
Help anyone can help me do this question,I will mark brainlest.
Explanation:
NA2SO3
Combination of these three elements forms following compounds.
And the compound that's going to be formed,depends on the ratio of available oxygen and sulphur.
Depends on the ratio of sulfur to oxygen...
sodium sulfate, Na2SO4
sodium sulfite, Na2SO3
sodium thiosulfate, Na2S2O3
ionic bond is present in between SO3 -2 and Na+2
structure of SO3 -2 [take - sign as delta - which here indicates,partial formal charge of oxygen] (image below)
Here,The oxygen is more electronegative.So,2 oxygen atoms drag one Electron from sulphur atom,leaving behind the formal charge of -1 on two oxygen atoms.
The third oxygen forms covalent bond by sharing 2 electrons. (Actually this ion has resonance structure)
This sulphite ion combines with two sodium ions to form two ionic bonds.This happens when sodium, being an alkali metal dontes it's valence electron to oxygen.
SO2
In Sulphur dioxide, Sulphur is bonded to 2 oxygen atoms. Oxygen is more electronegative than Sulphur and thus, shows a fixed valency of 2. As a result each oxygen forms two bonds with the Sulphur atom making its valency 4.
NAHSO4
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Questions & Answers
CBSE
Chemistry
Grade 11
Oxidation State or Oxidation Number
Question
Answers
Related Questions
The oxidation state of sulphur in NaHSO4 ?
A) 0
B) + 2
C) −2
D) + 4
E) + 6
Answer
VerifiedVerified
72.9K+ Views
Hint: The oxidation state is defined as the charge on the atom. The sum of the oxidation state of an atom in a molecule is equal to the charge on the molecule. The neutral molecules charge less species. It has zero charges.
Complete Solution :
- The oxidation number of an atom is defined as the charge on an atom that appears on the atom on forming an ionic bond. An atom which has higher electronegativity has a negative oxidation state and more electropositive elements have positive oxidation state.
- We are interested in determining the oxidation state of an atom in a molecule. We know that the net charge on a neutral atom or molecule is always equal to zero. Let’s determine the oxidation state of S in the NaHSO4 .
- The oxidation number of alkali metal that is a sodium atom is equal to +1 . Similarly the hydrogen has an +1 oxidation state. Oxygen is an electronegative element. It has an −2 oxidation state. The oxidation states are as listed below:
Element Oxidation state
Na +1
H +1
O −2
We know that the sum of the oxidation state of an atom in a neutral molecule is equal to zero. Then we have,
0 = O.S. of Na + O.S. of H + O.S. of S + 4(O.S. of O)
Let’s substitute the values of oxidation state .we have,
0 = 1 + 1 + O.S. of S + 4(−2)⇒O.S. of S= 8−2 = +6
Therefore the oxidation state of sulphur in NaHSO4 is equal to +6 . So, the correct answer is “Option E”.
H2S
Valency of sulphur is 2 in H2S
who knows india??????
Answer:
Me India is located in Asia and its capital name is New Delhi.
Explanation:
[tex]india \\ 1)india \: is \: the \: 7 \: th \: largest \: country \\ 2)home \: to \: old \: civilizations \\ 3)father \: of \: the \: nation \: mahathma \: gandi \\ 4)country \: is \: divided \: in \: to \: 28state \\ 5)1000of \: lnguages \: 100 \: of \: cultures \: \\ so \: india \: is \: very \: much \: attractive \\ very \: much \: special \\ 1947 \: august15 \: indias \: independce \: day \\ thank \: you \: \\ jai \: hind[/tex]