Answer:
A pure solid is heated and turns into a pure liquid.
Explanation:
No colour change recorded, only change of state, hence this is a physical change - physical changes I.e. change of state and temperature are not chemical reactions.
Which of the following statements best describes the relationship between the elements phosphorus (P), arsenic (As) and bismuth (Bi)?
A. The elements are in the same period because they have the same numbers of energy levels, but different reactivity.
B. The elements are in the same group because they have the same numbers of energy levels, but different reactivity.
C. The elements are in the same period because they have similar reactivity and the same number of valence electrons.
D. The elements are in the same group because they have similar reactivity and the same number of valence electrons.
Answer:
A
Explanation:
Balance the following equation.
___ I + ___ O2 ___ I4O10
Which of the following is NOT a physical property?
A. melting point
B. state of matter
C. density
D. flammability
Answer:
i think.its D ddddddddddddd
A nitrogen molecule (N2) has one triple bond. How many electrons do the nitrogen atoms share?
A. 1
B. 3
C. 4
D. 6
Answer:
3 electrons
Explanation:
What is the percent of Li in
Li3N?
(Li = 6.94 amu, N = 14.01 amu)
Answer:
The percentage by mass of lithium in one mole of Li₃N is approximately 59.78%
Explanation:
The given compound is Li₃N
The atomic mass of lithium, Li = 6.94 amu
The atomic mass of nitrogen, N = 14.01 amu
Therefore by definition, we have;
The mass of one mole of lithium, Li = 6.94 g
The mass of one mole of nitrogen, N = 14.01 g
One molecule of Li₃N contains 3 atoms of lithium, Li and 1 atom of nitrogen, N
The mass of one mole of Li₃N = The molar mass of Li₃N = 3 × The mass of one mole of lithium + The mass of one mole of nitrogen
∴ The mass of one mole of Li₃N = 3 × 6.94 g + 14.01 g = 34.83 g
The percentage by mass of lithium, Li, in one mole of Li₃N = 3×6.94/(34.83) × 100 ≈ 59.78%
The percentage by mass of lithium in one mole of Li₃N ≈ 59.78%.
Describe the classification of electromagnetic radiation.
Answer:
The EM spectrum
Explanation:
The EM spectrum is generally divided into seven regions, in order of decreasing wavelength and increasing energy and frequency. The common designations are: radio waves, microwaves, infrared (IR), visible light, ultraviolet (UV), X-rays and gamma rays.
what does an atomic emission spectrum look like if the electrons energy levels in an atom were not quantizied
a. lines would be shifted into the ultraviole region
b. there would be fewer lines
c. there will be more lines
d. the spectrum would be constnuous
Answer: The spectrum would be continuous
Explanation:
Atomic transitions allow us to find that the correct answer to what would happen if there was no quantization is:
d. the spectrum would be continous
In the models of atoms the correct explanation for the energy was given by Planck, by establishing that the energy of an electron is:
E = h ν
Where E is the energy, h the Planck constant and ν the frequency.
Therefore a transition occurs as the jump of an electron from one level to another
ΔE = E₂ - E₁
In all atomic models the levels are discrete, so the jumps are also discrete.
If the levels were continuous, the energy difference between the lines disappears and we have a continuous emission spectrum.
Let's review the different answers:
a. False. The lines disappear
b. False. This for if the separation between levels increases, which is the opposite process to the one analyzed.
c. False. The lines disappear
d) True. The spectrum is a continuum without any separation.
In conclusion, using the atomic transitions we find that the correct answer for what would happen if there was no quantization is:
d. the spectrum would be constnuous
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What goes in cellular respiration and what comes out of cellular respiration?
Oxygen and glucose are both reactants in the process of cellular respiration. The main product of cellular respiration is ATP; waste products include carbon dioxide and water.
Exactly how many planes contain points J, K, and N?
O 0
O 1
O 2
O 3
Answer:
0
Explanation:
Point J is on neither plane X or plane Y. Hope this helps you.
Answer:
3
Explanation:
Name the Ionic Compounds listed below.
1.) Al2O3 =
2.) NaCl=
3.) MgO =
4.) CaCl2=
Answer:
1. Aluminum oxide
2. Sodium chloride
3. Magnesium oxide
4. Calcium Chloride
Explanation:
Ionic compounds with only 2 elements all end with "ide" Use the full name of the element listed first and the second element with ide. Ex: Chlorine would become chloride.
Answer:
Explanation:
1. Al2O3 = Aluminum Oxide
2. NaCl = Sodium Chloride
3. MgO = Magnesium Oxide
4. CaCl2 = Calcium Chloride
In a lever,E×E.D.=L×__________
Answer:
LD is a answer okkkkkkkkkkkkkkkkk
PLEASE HELP, I WILL MAKE YOU THE BRAINLIEST!!!
3. Magnesium sulfate is added to sodium hydroxide to produce sodium sulfate and magnesium hydroxide (10 points)
a. Write the skeletal equation and Balance the chemical equation describing the reaction above.
b. What kind of reaction is this?
c. Rewrite the balanced chemical equation, adding state symbols for all compounds in the reaction.
Answer:
answer in the picture hi shirllleeyyyyy
What causes metal atoms to form metallic bonds?
Answer:
Metallic bond, force that holds atoms together in a metallic substance. ... The atoms that the electrons leave behind become positive ions, and the interaction between such ions and valence electrons gives rise to the cohesive or binding force that holds the metallic crystal together.
Explanation:
A photon has a wavelength of 299 nm. What is the frequency of this photon?
1. 1×10^16 Hz
2. 1×10^15 Hz
3. 6.65 × 10^−37 Hz
4. 6.65 × 10^−28 Hz
5. 0.00100 Hz
6. 1.98 × 10^−31 Hz
7. 8.97 × 10^10 Hz
8. 1×10^6 Hz
9. 6.65 × 10^−18 Hz
The frequency(f) of this photon : 1 x 10¹⁵ Hz
Further explanationRadiation energy is absorbed by photons
The energy in one photon can be formulated as
[tex]\large{\boxed{\bold{E\:=\:h\:.\:f}}}[/tex]
Where
h = Planck's constant (6,626.10⁻³⁴ Js)
f = Frequency of electromagnetic waves
f = c / λ
c = speed of light
= 3.10⁸
λ = wavelength
A photon has a wavelength of 299 nm.
λ = 299 nm = 299 x 10⁻⁹ m = 2.99 x 10⁻⁷ m
The frequency :
[tex]\tt f=\dfrac{3.10^8}{2.99\times 10^{-7}}\\\\f=\boxed{\bold{1\times 10^{15}~Hz}}[/tex]
Please answer correctly !!!!!!!!!!!!! Will mark brainliest !!!!!!!!!!!!!!!!!!!!
Answer:
AG
Explanation:
HOPE THIS HELPS
Is nuclear energy poised to be part of America’s future?
Answer:
Nuclear energy powers our businesses, homes and military. America’s 95 operating nuclear reactors generate approximately 20% of our nation’s electricity and provide over half of our carbon-free energy. They also create good-paying jobs at power plants and uranium mines. Wyoming produced 87% of America’s domestic uranium supply in 2018.
Today, nuclear energy faces serious hurdles. Regulatory costs and subsidies for renewable energy technologies are forcing America’s nuclear power plants to close at an alarming rate.
Russia and China are subsidizing their government-owned nuclear companies to assert their energy influence around the world. China is searching the globe for uranium reserves and investing heavily in the countries where it’s found. They want to secure more nuclear fuel for themselves and increase their control of the global supply.
Meanwhile, American nuclear power plants have come to rely on cheap Russian imports of uranium to meet their nuclear fuel needs. Right now, roughly 40% of the uranium coming into the United States originates in Russia or its satellite states of Kazakhstan and Uzbekistan. Russian-backed companies are developing fuel that can be placed directly in American reactors.
Explanation:
Predict the precipitate that will be formed in the following reaction:
NaF(aq) + AgNO3(aq) →
The precipitate that will be formed : AgF
Further explanationOne indication of the double displacement reaction is the precipitation reaction
Solubility Rules:
• 1. soluble compound
All compounds of Li +, Na +, K +, Rb +, Cs +, and NH4 +
All compounds of NO₃⁻ and C₂H₃O₂⁻
Compounds of Cl−, Br−, I− except Ag⁺, Hg₂²⁺, Pb²⁺
Compounds of SO₄²⁻ except for Hg₂²⁺, Pb²⁺, Sr²⁺, Ba²⁺
• 2. insoluble compounds
Compounds of CO₃²⁻ and PO₄³⁻ except for Compounds of Li +, Na +, K +, Rb +, Cs +, and NH₄ +
Compounds of OH− except Compounds of Li +, Na +, K +, Rb +, Cs +, NH₄⁺, Sr²⁺, and Ba²⁺
Reaction
NaF(aq) + AgNO₃(aq) →NaNO₃(aq)+ AgF(s)
From the solubility rules above, it has been shown that the salts of the Ag⁺ cations are insoluble salts
The periodic table includes all of the known elements in the world. How are elements
arranged on the periodic table?
a. by the element's name
b. by their atomic mass
c. by the number of neutrons found in the element
d. by their atomic number
Answer: D: by their atomic number
Explanation:
Elements are arranged from left to right and top to bottom in order of increasing atomic number. Order generally coincides with increasing atomic mass. The rows are called periods
If an element has 11 protons and 11 neutrons in its nucleus it must be ?
Answer:
the answer is 11
Explanation:
Ok, let us understand what is an atomic number, an atomic number is simply the proton number, the atomic number is always seen at the bottom left corner in a element of a periodic table, it is the number of proton in a atom of a certain element.
What type of reaction does each of the following equations represent?
A. Single replacement
B. Double replacement
C. Decomposition
Answer:
Option C. Decomposition
Explanation:
To know which option is correct, it is important we know what is a single displacement reaction, double displacement reaction and decomposition reaction.
A Single displacement reaction can be defined as a reaction in which a single element is replaced by another element in a compound.
A double displacement reaction is a reaction involving the exchange of ions of two parts of ionic compounds to form two different compounds.
A decomposition reaction is a reaction in which a compound splits into two or more simpler compound or element.
Bearing the above definitions in mind and considering the question given above, we can conclude that the reaction given in the question above is a decomposition reaction since the compound (NH₄OH) splits into two different compound (NH₃ and H₂O)
Question 14
An element's periodic table identity is defined by its number of
А.
neutrons.
B
isotopes.
С C
electrons.
protons
Answer:
c
Explanation:
protons are the atomic number which define an element
Aqueous solutions of sodium carbonate and magnesium chlorate are mixed
Explanation:
You're mixing magnesium nitrate, Mg(NO3)2 , and sodium carbonate, Na2CO3 , two soluble ionic compounds that dissociate completely in aqueous solution to form cations and anions.
can I get help please
Consider the balanced equation. PCl3 + 3H2O Right arrow. H3PO3 + 3HCl What is the percent yield of HCl if 42.0 g of HCl are produced from the reaction of 62.0 g of PCl3? Use Percent yield equals StartFraction actual yield over theoretical yield EndFraction times 100..
Answer:
Percient yield of reaction: 85 %
Explanation:
The reaction is:
PCl₃ + 3H₂O → H₃PO₃ + 3HCl
We only have data from the chloride, so we assume water is in excess. We convert the mass to moles:
62 g . 1mol / 137.32 g = 0.452 mol
If ratio is 1:3, from 0.452 mol we would produce three times as big, that amount. (0.452 . 3) = 1.36 moles of HCl.
We convert the amount to mass.
1.36 mol . 36.45g / 1mol = 49.4 g
This value of produced HCl is the theoretical yield. To determine the percent yield we make:
(Yield produced / Theoretical yield) . 100
(42 g / 49.4g) . 100 = 85%
Answer:
Yes it is 85.0%
Explanation:
Some consumers, like lions, do not eat plants or any other producers. They only eat other animals.
How do lions obtain the carbon they need?
by eating animals that have carbon-based molecules stored in their bodies
by breathing it in from the atmosphere in the form of carbon dioxide
by absorbing carbon-based molecules through their skin from the soil
by drinking water that contains carbon dioxide
Answer:
a
Explanation:
Some consumers, like lions, do not eat plants or any other producers. They only eat other animals. lions obtain the carbon they need by eating animals that have carbon-based molecules stored in their bodies and the correct option is option 1.
What are Consumers?Heterotrophs are known as consumers because they consume producers or other consumers. Heterotrophs occupy the second and third levels in a food chain, a sequence of organisms that provide energy and nutrients for other organisms.
Heterotrophic living organisms include all animals and fungi, some protists and bacteria, many types of parasitic plants.
Carnivores (organisms that eat meat) and omnivores (organisms that eat plants and meat) occupy the third level.
Therefore, Some consumers, like lions, do not eat plants or any other producers. They only eat other animals. lions obtain the carbon they need by eating animals that have carbon-based molecules stored in their bodies and the correct option is option 1.
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Compared to ionic compounds, molecular compounds generally have
A. stronger chemical bonds.
B. poor conductivity.
C. a high melting point.
D. lower densities.
Which choices are layers of the atmosphere?
Select the five correct answers.
Thermosphere
Meteorosphere
Croposphere
Stratosphere
Mesosphere
Danosphere
Exosphere
Troposphere
Answer:
Mesosphere
Stratosphere
Thermosphere
Troposphere
Exosphere
Explanation:
The exosphere refers to the farthest region of the atmosphere that gradually fades into space.
The troposphere is the lowest layer of atmosphere. It is the layer where weather changes occur.
The thermosphere is right above the mesosphere but just below the exosphere. It is the layer where photoionization/photodissociation of molecules occurs thereby creating ions. This largely owes to interaction of molecules in this layer with ultraviolet radiation.
The stratosphere is composed of gases. Prominent among them is ozone which serves as a blanket against the sun's ionizing radiation.
The mesosphere lies above the stratosphere but just below the thermosphere. Temperature decreases steadily with height in the mesosphere.
Which of these statements describes the basic idea of the Valence Shell
Electron Pair Repulsion (VSEPR) theory?
1. Molecules repel one another due to intermolecular forces.
2. There is always an octet of electrons around an atom in a molecule
3. Shared and unshared electron pairs repel each other as much as
possible
4. Electrons are attracted to the nucleus of the central atom.
Answer:
3. Shared and unshared electron pairs repel each other as much as
possible
Explanation:
The variations in the bond angles of molecules and ions can be explained using the valence shell electron pair repulsion theory.
The VESPR model determines the total number of electron pairs (TEP) surrounding the central atom of a specie. The TEP consists of bond pairs BP and lone pairs LP.
All the electron pairs will orient themselves in such a way as to minimize the electrostatic repulsion between them.
The repulsion determines the geometry of the covalent bonds around the central atom. As the number of lone pairs increases from 0 to 2, the bond angles diminishes progressively.
Provide your answer in the following format: [element name], [chemical family]
Answer: Bismuth (Bi) , Nitrogen family
Explanation:
As the element has 5 valence electrons in the sixth energy level, which mens it belongs to 6th period as the valence electron has entered the 6th energy level.
Now as the electrons are filled according to afbau's rule , the electronic configuration of the element will be :
[tex][Xe]4f^{14}5d^{10}6s^26p^3[/tex]
Now as the atomic number of element is equal to the number of electrons in a neutral atom , the atomic number is 83 and the element is Bismuth (Bi). As the last electron enters p -subshell , it is a p block element. It lies in group 15 which is nitrogen family.
Fill in the blanks. A person would weight more on Neptune than on planet blank
because
blank
A person would weigh more on Neptune than on planet earth because the gravitational field strength is stronger on Neptune.
A person would weight more on Neptune than on planet earth because the gravitational force in neptune is more.
What is gravitational force?Gravitational forces is a kind of attraction force which is present between two objects of masses.
Gravitational force on the neptune planet is more as compared to the gravitational force on the earth. So the mass of any object present in the neptune is more than the earth.
Hence a person would weight more on Neptune than on planet earth because gravitatinal force in neptune is more.
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