Answers
Answer:
1.c 2.a.3.d 4.a
Explanation:
that is tge answer
Related Questions
Which of the following is NOT a sign of a chemical change? (HINT: only 2 answers, the rest are chemical change)
1. tarnished is formed
2. gas is produced
3. weight change
4. Temperature change
5. color change
6. nothing changes
7. forms a precipitate
8. energy is released
Need this done today please!!
Answers
Answer:
3 and 6 (weight change and nothing changes)
Explanation:
Hi there!
A chemical change is a change when matter changes into a new substance and has a new chemical property.
The signs that a chemical change is taking place are:
1. change in color
2. change in smell
3. change in energy (for example, there is a change in temperature (thermal energy))
4. a gas is formed (fizzing/bubbling/foaming are signs of this!)
5. formation of a solid (a precipitate)
A physical change is any change to the size, shape, or state of a substance. The substance still has the same chemical property.
these are your eight options:
1. tarnished is formed (a sign of a chemical change; a change in color)
2. gas is produced (a sign of a chemical change)
3. weight change (NOT a sign of a chemical change. Even though the weight changed, the substance still has the same chemical composition and therefore, there wasn't any change to its chemical identity)
4. Temperature change (a sign of a chemical change; a change in energy)
5. color change (a sign of a chemical change)
6. nothing changes (NOT a sign of a chemical change. If nothing happens, the substance is still the same as it was originally and there was no change to its chemical identity.)
7. forms a precipitate (a sign of a chemical change)
8. energy is released (a sign of a chemical change)
therefore the two options that are NOT a sign of a chemical change are 3 and 6 (weight change and nothing changes)
Hope this helps! :)
What does it mean if an element has 8 valence electrons?
Answers
Answer:
the answer is the D, it has a full octet
If the half-life of Sulfate-12 is 18 years, how much of a 6 gram sample is left after 2 half-lives?
Answers
Answer:
The correct answer is - 1/4 0f 6 gram or 1.5 gram to be exact.
Explanation:
Given:
Half-life of sulfate-12 = 18 years
number of half-lives - 2
initial amount - 6 grams.
Solution:
The Half-life of an element or substance is the required time to decay the half amount of the initial amount of the element.
Remaining amount = initial amount * (1/2)^n
here n = number of half lives
then,
Remaining amount = 6* (1/2)^2
= 6/4
= 1.5 g.
Thus, the correct answer is = 1.5 g or 1/4 of 6 gram.
All molecules have London forces between them, but dipole-dipole and hydrogen bonding are so much stronger that when they are present we
can ignore London forces. Only NONPOLAR molecules will SHOW LDF. Which of these has ONLY LDFs?
A. I2
B. HF
C. NH3
D.H2S
Answers
Answer:
a
Explanation:
khan academy
Among the options given, only [tex]I_2[/tex] shows London-Dispersion forces. Thus, the correct option for this question is A.
What is the London-Dispersion force?The London-Dispersion force may be defined as a type of provisional attractive force that arises when the electrons in two adjacent atoms tenanted positions that construct the atoms to form temporary dipoles. It is considered the weakest intermolecular force.
[tex]H_2S[/tex] shows dipole-dipole interactions because hydrogen and sulfur have huge electronegative differences. Due to this, their bonds are polar. [tex]NH_3[/tex] shows hydrogen bonding between them. HF shows dipole-dipole interactions because it is a polar covalent molecule.
Therefore, only [tex]I_2[/tex] shows London-Dispersion forces. Thus, the correct option for this question is A.
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shakajskwbskam help?
Answers
Answer:
beta
Explanation:
Write the balanced chemical equation for the reaction of glucose (C6,H12,O6) with oxygen gas to produce carbon dioxide gas
and water vapor.
Answers
Answer:
C6H12O6+6O2=6Co2+6H2o
The balanced chemical equation for the reaction of glucose (C₆H₁₂O₆) with oxygen gas to produce carbon dioxide gas and water vapor is C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O
What is Balanced Chemical Equation ?
The balanced chemical equation is the equation in which the number of atoms on the left hand side that is reactant side is equal to the number of atoms on the right hand side that is product side in an equation.
The balanced chemical equation is:
C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O
Thus, from the above conclusion we can say that The balanced chemical equation for the reaction of glucose (C₆H₁₂O₆) with oxygen gas to produce carbon dioxide gas and water vapor is C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O
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Which of these is a reason why nuclear power is important?
O A. Solar technology provides an endless source of power.
B. Solar and wind technologies are both types of "green" energy.
O C. Fossil fuels will run out soon.
D. Wind technology is being utilized in places where there is a lot of
wind.
Answers
Answer:
C Fossil fuels will run out soon
Nuclear energy is the most important energetic source against the shortage of fossil fuels as oil and methane. Nuclear power are a significant contribution to total electricity production; about 20% in the United states. It involves the use of nuclear reactions that release nuclear energy to generate heat, which most frequently is then used in steam turbines to produce electricity within a nuclear power plant
How many moles of Mercury ll oxide are needed to produce 125g of o2
Answers
types of radioactive nuclide
Answers
Answer:
On Earth, naturally occurring radionuclides fall into three categories: primordial radionuclides, secondary radionuclides, and cosmogenic radionuclides. Radionuclides are produced in stellar nucleosynthesis and supernova explosions along with stable nuclides.
Which sequence represents a portion of a
homologous series of hydrocarbons?
1.
C2H2, C2H4, C2H6
2.
C2H2, C3H4, C6H6
3.
C2H4, C3H4, C4H4
4.
C2H4, C3H6, C4H8
Answers
Answer:
4. C2H4, C3H6, C4H8
this is the alkane homologous series of hydrocarbons.
Their general formula is CnH2n
you can check this fits for all these compounds
put n = 1, 2, 3 and so on
A 9.583 L contains nitrogen gas under a pressure of 4.972 atm at
31.8°C. Calculate the number of moles of nitrogen in the tank.
Answers
Answer:
0.0188
Explanation:
using pv=nRt
where v--volume
p pressure
n number of moles
t temperature in kelvin
R molar gas constant=8.314atmmoldm^-3k^-1
4.972 × 9.583 =n × 8.314 × (31.8 + 273)
note I changed 31.8c to kelvin
making n subject of the formula
n=(4.972 × 9.583)/(8.314 ×(31.8 + 273)
n=(4.972 × 9.583)/(8.314 ×(304.8))
n=0.0188 moles
What method could be used to separate the
components of gasoline?
Answers
Answer:
Distillation
Explanation:
Reason being the process is only used to separate liquids with boiling points greater than 25 °C
Answer:
b
Explanation:
correct on edge
Question 21
Which equation is a balanced chemical equation?
A
2NaOH + CaBr2 + Ca(OH)2 + NaBr
B
NO + Cl2 → NOCI
с
CaCO3 + CaO + 2CO2
D
2AlCl3 + 3Mg + 3MgCl2 + 2A|
D
B
Ос
ОА
Answers
Answer:
the equation is not correctly written but the answer is option D
The balanced equation among the given options is D, where each of the elements are equal in number on both side.
What is balanced reaction?A balanced chemical equation for a reaction represents perfect stoichiometric ratios of each reactants and products. Each elements have to be equal in number on both sides.
The number of elements or groups can be balanced each side by multiplying with suitable integers. The chemical equation in D is balanced where, Al, Cl and Mg are balanced on both side.
The equation in A, is not balanced where, number of Na and Br are not balanced. In equation B Cl is two in reactant side and one in product side. Thus, not balanced. Similarly in option C, oxygen and calcium are not balanced. Therefore, option D is correct.
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Las levaduras son microorganismos usados en la industria alimentaria en diversos procesos, uno de ellos es la fermentación del azúcar para producir alcohol, tal como se representa en el esquema. LEVADURA + AZÚCAR + CALOR ⇒ Dióxido de carbono + alcohol ¿Por qué este proceso se considera una reacción química? *
Porque solamente hay un aumento de temperatura.
Porque el azúcar cambia de estado.
Porque el azúcar se transforma en otra sustancia.
Porque el alcohol se evapora rápidamente.
Answers
Respuesta:
Porque el azúcar se transforma en otra sustancia.
Explicación:
Consideremos el cambio representado en el siguiente esquema.
LEVADURA + AZÚCAR + CALOR ⇒ Dióxido de carbono + alcohol
¿Por qué este proceso se considera una reacción química?
Porque solamente hay un aumento de temperatura. NO. El aumento de temperatura no indica una reacción química. Porque el azúcar cambia de estado. NO. El azúcar no cambia de estado. Porque el azúcar se transforma en otra sustancia. SI. En una reacción química, unas sustancias (reactivos) se transforman en otras (productos). Porque el alcohol se evapora rápidamente. NO. La evaporación es un cambio físico.summarize what you know about carbon
Answers
Answer:
Carbon is a chemical element, like hydrogen, oxygen, lead or any of the others in the periodic table. Carbon is a very abundant element. It exists in pure or nearly pure forms – such as diamonds and graphite – but can also combine with other elements to form molecules.
Which characteristic of water allows its molecules to form hydrogen bonds? (1 point)
Answers
Answer:
Water molecule is polar.
Explanation:
The partial negative charge on the O of one molecule can form a hydrogen bond with the partial positive charge on the hydrogens of other molecules.
How many moles of NaCl are present in 23.5 grams of NaCl?
Answers
Answer:
0.342 mol
Explanation:
Molar mass of
NaCl = 58.4 g/mol
Number of moles in
20.0 g NaCl
is
20.0
g
58.4
g
/mol
=
0.342 mol
15. Which of the following elements will not form a polar covalent bond with oxygen? A. Sodium B. Fluorine Oxygen D. Hydrogen
Answers
Answer:
C. oxygen
Explanation:
oxygen cannot for a polar covalent bond with another oxygen atom
Answer:
oxygen
Explanation:
Calculate the atomic mass of Nitrogen if the two common isotopes of Nitrogen have masses of 31.972 amu (85.00 %
abundance) and 33.967 amu (15.00% abundance)
Answers
Explanation:
hope the picture above help u understand:)
9. The prefix oct- means
That there are
8 hydrogen atoms
8 carbon atoms
8 single bonds
8 double bonds
Answers
Answer:
2nd option
Explanation:
it means that there are 8 carbons
The prefix oct- mean that there are 8 carbon atoms. Therefore, option (B) is correct.
What are the steps for the IUPAC nomenclature?The 1st step for the IUPAC nomenclature of a compound is to select the longest, most substituted carbon chain with a functional group. Then the use of the primary suffix indicates the degree of unsaturation such as 'ane' or 'ene.
Then the identification of the secondary suffix indicates the number of functional groups in the molecule and the number of times of the same functional group such as di, tri, tetra, etc.
The prefix can be used to indicate the side chains, substituents, and low-priority functional groups. The prefix Oct- is used if there are eight carbon atoms in the chain. The prefix 'ane' is used for single bonds and the prefix 'ene' is used for the double bonds in the carbon chain.
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Why does water appear blue?
A. Because the sky is reflecting on the water
B. Because of the way the water molecules are moving
C. Because of blue-colored elements dissolved in the water
Answers
Because if you were to be in a room with orange lights the water would appear orange and glowing. Same thing with other colors this is because the sun rays pass through the atmosphere reflecting from a pure white light to a lighter blue and reflecting off of the waters surface.
PLEASE HELP PLS LFHLFATOI;RHG
Answers
Answer:
C. A model of a water molecule
Explanation:
H20, model shows 2 H,s (H2) and 1 O (O) which makes H2O. It's a model and not a real life picture of a molecule.
Answer:
C. A model of a water moleculeExplanation:
2 hydrogen + Oxygen= water molecule#CarryOnLearning
[tex]{.hope (it helps}}) [/tex]
Hydrogen bonding occurs when hydrogen is bonded to N, O, or F. Which of the following molecules has hydrogen bonding, when bonding with
their same molecules?
A. CBr4
O B.H2S
C. NO2
OD. NH3
Answers
Answer:
I think the answer is……
O B.H2S
Explanation:
I’m not sure tho, I’m just not 100% positive.
Explain the steps needed to obtain an ammonium salt
Answers
Answer:
When an amine is added to a solution of a strong acid, such as hydrochloric acid, the amine nitrogen atom is protonated to produce an ammonium salt. Ammonium salts of low molecular weight are soluble in water if the hydrocarbon portion of the amine is small.Ammonium cation is found in a variety of salts such as ammonium carbonate, ammonium chloride and ammonium nitrate. Most simple ammonium salts are very soluble in water. An exception is ammonium hexachloroplatinate, the formation of which was once used as a test for ammonium.
What can a drop of liquid mercury be described as?
a pure substance and a compound
an impure substance that is reactive
an impure substance that is unreactive
a pure substance and an element
Answers
Answer:
a pure substance and an element”
Explanation:
Which pure substance can be classified as an element?
Answers
Answer:
A substance that cannot be broken down into chemically simpler components is an element.
Aluminum, which is used in soda cans, is an element.
energy the ability to do ____ or cause ____ its measured in _____ and is found in many different _____. energy can be classified as _____ or _____ energy
PLS HELP QUICK!!!!!
Answers
Why does CCl4 dissolve in iodine
Answers
Answer: They are both non polar molecules compounds although water is a polar molecule compound. There are no significant attractions.
2500 cal of heat are absorbed by 150 grams of water that is initially at 23°C, what is the final temperature of the water?
Answers
Answer:
H=MC∆T
Heat = Heat absorbed or given off
M=Mass
C=Specific Heat Capacity of substance (Water in thus case). It has a Specific Heat capacity of 4200J/kg.k
∆T= Temp Change (T2-T1)
I'll solve with My Heat in Joules.
The heat is given in Calorie
1Cal = 4.186J
2500cal = 10,465J.
∆T= H/MC
=10465/0.15(4200)
=16.6°C
∆T=16.6
T2 - T1 = 16.6
T2 = 16.6+T1
T2 = 16.6 + 23
T2 = 39.6
Approx. 40°C
What is the amount of sodium hydroxide, NaOH, in 4.6 g? Use the values given for
the atomic mass of Na, H, and O.
6
Na = 22.989 770 u
H = 1.007 94u
0 = 15.99944
9
a) 0.19 mol
12
b) 0.12 mol
15
c) 1.8 x 102 mol
d) 0.20 mol
Answers
Answer: 0.12 Mol
Explanation: Molecular mass of NaOH is = 39,997 g/mol which is Atomic mass of Na + Atomic Mass of H + Atomic mass of O
4.6g / 39.997g/mol = 0.12 mol