Answer:
The moon
Explanation:
The moon pulls on the earth, causing the tides to raise as the water is being pulled by the moon.
The purpose of a thermostat on a hot water boiler is:
Beta-carotene and lutein are carotenoids. What is the primary color that they absorb (and therefore not reflect)
Answer:
Carotenoids absorb light in the blue-green and violet region
Explanation:
Carotenoids are organic pigments of yellow, orange, and red colour that are produced by plants and algae, bacteria, and fungi. Such organic pigments give the characteristic colour to pumpkins, corn, tomatoes, shrimp, and lobster. Carotenoids are also called as tetraterpenoids.
Beta-carotene and lutein are carotenoids. Carotenoids absorb light in the blue-green and violet region.
Which of the following statements is/are correct? i. Principal energy levels are identified by the letters s, p, d, and f. ii. Principal energy levels appear in both the quantum mechanical model of the atom and the Bohr model of the atom. iii. In general, n = 1 is at lower energy than n = 2, and n = 2 is lower than n = 3, and so on. iv. The principal energy level is related to electron spin. a. i only b. iv only c. i and ii d. ii and iii e. iii and iv
Answer:
d. ii and iii
Explanation:
Both the Bohr model and the wave (quantum) mechanical models of the atom recognize the principal quantum number n. The principal quantum number shows the shell or energy level where an electron may be found.
The energy levels are arranged in increasing order of magnitude. That is n=1 >n=2=n=3 etc
Complete and balance each of the following equations for acid-base reactions.
H3PO4(aq) + Sr(OH)2(aq) →
Explanation:
Sr(OH)2 + H3PO4 = Sr3(PO4)2 + H2O - Chemical Equation Balancer.
Answer:
3Sr(OH)2 + 2H3PO4 → Sr3(PO4)2 + 6H2O
Explanation:
please check the image for accurate answer
What tool do scientists use to classify animals?
Scientists use a two-name system called a Binomial Naming System. Scientists name animals and plants using the system that describes the genus and species of the organism. The first word is the genus and the second is the species.
Compound X has the formula C8H12. X reacts with two molar equivalents of hydrogen in the presence of a palladium catalyst to form cyclooctane. Treatment of X with ozone followed by zinc in aqueous acid gives two molar equivalents of the same dialdehyde. What is the structure of X
Answer:
See explanation and image attached
Explanation:
If we look at the question closely, we will discover that two molar equivalents of hydrogen gas was used to obtain cyclooctane rom X. This implies that the compound X is an alkyne and it must be cyclooctyne since the hydrogen serves to reduce the triple bond and yield the corresponding alkane.
This is confirmed by the second statement which is ozonolysis of the X with zinc in aqueous acid which gave two molar equivalents of the same dialdehyde.
Image credit: Chem spider
Many plants are poisonous because their stems and leaves contain oxalic acid, H2C2O4, or sodium oxalate, Na2C2O4. When ingested, these substances cause swelling of the respiratory tract and suffocation. A standard analysis for determining the amount of oxalate ion, C2O 2− 4 , in a sample is to precipitate this species as calcium oxalate, which is insoluble in water. Write the net ionic equation for the reaction between sodium oxalate and calcium chloride, CaCl2, in aqueous solution.
Answer:
Explanation:
Calcium chloride is a soluble salt which dissociates into calcium and chloride ions when dissolved in water.
CaCl₂(aq) ----> Ca²⁺(aq) + 2Cl⁻(aq)
Similarly, sodium oxalate when dissolved in water dissociates into sodium and oxalate ions.
Na₂CO₄(aq) ----> 2Na⁺(aq) + C₂O₄²⁻(aq)
However, in a double displacement reaction where the two solutions of the salts are mixed, the insoluble salt calcium oxalate is precipitated. The net ionic equation for the reaction is shown below:
Ca²⁺(aq) + C₂O₄²⁻(aq) ----> CaC₂O₄(s)
2.0 moles of sodium (Na) would have a mass of-
A) 0.087 grams
B) 46 grams
C) 1.2 x 10^24 grams
D) 3.3 x 10^-24
What is inside a Atom?
Answer:
there are three different subatomic particles inside them: the protons, neutrons, and electrons
Complete the passage. K (potassium) belongs to group IA of the periodic table, and has 1 valence electron. Br (bromine) belongs to VIIA, and has valence electrons. answer= 7
Answer:
See detailed explanation.
Explanation:
Hello.
In this case, since the electron configuration of potassium whose atomic number is 19 turns out:
[tex]K^{19}: 1s^2,2s^2,2p^6,3s^2,3p^6,4s^1[/tex]
We can see that the last level is 4 which has one electron, meaning that potassium has one valence electron. Moreover, since bromine's atomic number is 35, its electron configuration is:
[tex]Br^{35}: 1s^2,2s^2,2p^6,3s^2,3p^6,4s^2,3d^{10},4p^5[/tex]
We can see that the last level is also 4 and it has 2+5 = 7 valence electrons. In such a way, we infer that the valence electrons are computed by the electrons at the outer or last energy level of an element.
Regards.
Answer:
7
Explanation:
Each student in a class placed a 2.00 g sample of a mixture of Cu and Al in a beaker and placed the beaker in a fume hood. The students slowly poured 15.0 mL of 15.8 M HNO3 into their beakers. The reaction between the copper in the mixture and the HNO3 is represented by the equation above. The students observed that a brown gas was released from the beakers and that the solutions turned blue, indicating the formation of Cu 2. The solutions were then diluted with distilled water to known volumes. The students determined that the reaction produced 0.010 mol of Cu(NO3)2. Based on the measurement, what was the percent of Cu by mass in the original 2.00 g sample of the mixture
Answer:
Percentage mass of copper in the sample = 32%
Explanation:
Equation of the reaction producing Cu(NO₃) is given below:
Cu(s)+ 4HNO₃(aq) ---> Cu(NO₃)(aq) + 2NO₂(g) + 2H₂O(l)
From the equation of reaction, 1 mole of Cu(NO₃) is produced from 1 mole of copper. Therefore, 0.010 moles of Cu(NO₃) will be produced from 0.010 mole of copper.
Molar mass of copper = 64 g/mol
mass of copper = number of moles * molar mass
mass of copper = 0.01 mol * 64 g/mol = 0.64 g
Percentage by mass of copper in the 2.00 g sample = (0.64/2.00) * 100%
Percentage mass of copper in the sample = 32%
What is the speed of each vehicle? (Remember S=d/t)
A: 50 km/h, B: 40 km/h
A:5 km/h, B: 2 km/h
A: 10 km/h, B: 5 km/h
A: 20 km/h, B: 10 km/h
Answer : The correct option is A: 20 km/h, B: 10 km/h
Explanation :
Speed : It is defined as the distance traveled per unit time.
Formula used:
[tex]S=\frac{d}{t}[/tex]
where,
S = speed
d = distance
t = time
First we have to calculate the speed of vehicle A.
Given:
Distance of vehicle A = 50 km
Time of vehicle A = 2.5 hr
Now putting all the given values in the above formula, we get:
[tex]S=\frac{50km}{2.5hr}=20km/hr[/tex]
Now we have to calculate the speed of vehicle B.
Given:
Distance of vehicle B = 50 km
Time of vehicle B = 5 hr
Now putting all the given values in the above formula, we get:
[tex]S=\frac{50km}{5hr}=10km/hr[/tex]
Therefore, the speed of vehicle A and B is 20 km/hr and 10 km/hr respectively.
By which method is heat transferred in a microwave oven?
Conduction
Convection
Evaporation
Radiation
Answer:
the answer is radiation.
because the microwave is a form of radiation.
give me brainlyest if this was helpful to you otherwise dont.
Answer: D
Explanation:
How are gases and liquids different from each other? O A. Liquids can change volume, and gases cannot. B. Gases can change shape, and liquids cannot. C. Liquids can change shape, and gases cannot. D. Gases can change volume, and liquids cannot.
Answer:
d
Explanation:
d is the right answer since gases do not have definite shape and volume and liquids have definite volume. so liquid cannot change its volume but gas can
which of the substances created a chemical change
Answer:
It is one and two
Explanation:
When you burn something it lights up
elasric energy is a type of kenetic energy true or false
Answer:
False
Explanation:
A student loaded a mixture of compounds onto a silica gel column using 5 mL of dichloromethane as the loading solvent. After running the column using petroleum ether as the eluant and collecting 8 fractions, the student analyzed the contents by TLC to find that all of the compounds in the mixture came off in the first two fractions. In addition, no separation was observed. Choose the statement that BEST describes the error. The sample should be loaded using a maximum 1 mL of CH2Cl2. Petroleum ether was the incorrect eluant. A more polar solvent should have been used. The student should re-run the TLC. It was obviously performed incorrectly. The student packed the column incorrectly.
Answer:
Petroleum ether was the incorrect eluant.
Explanation:
In column chromatography, there must be a mobile phase (eluant) and a stationary phase(adsorbent column). The mobile phase in this case is petroleum ether while the stationary phase is silica gel.
If no separation is observed, then it simply means that the wrong choice of mobile phase(eluant) was made. If a better choice of eluant is made, it can effectively achieve the separation of the mixture. The components of the mixture have a great affinity towards the petroleum ether hence they moved rapidly through the column and separation was not achieved.
When naming CoOH, which Roman numeral should be used?Immersive Reader
(A) I
(B) II
(C) III
(D) IV
PLZ HELP I'LL MARK BRAINLIEST
Answer:
coochie man? lol it's probably D or B :D
The elwments in group 17 of the periodic table are all halogens. All halogens have the same ______.
A. Atomic number
B. Atomic mass
C. Number of possible isotopes
D. number of valence electrons
Group 17 elements called halogens . All halogens have the same number of valence
electrons
If air has a density of 1.225 kg/m3, what is the mass of the air in a hot air balloon that has a volume of 2,800
m3?
Answer:
The answer is 3430 kgExplanation:
The mass of a substance when given the density and volume can be found by using the formula
mass = Density × volumeFrom the question
volume = 2800 m³
density = 1.225 kg/m³
We have
mass = 2800 × 1.225
We have the final answer as
3430 kgHope this helps you
Which property is not a physical property?
A. Color
B. Ability to Burn
C. Density
D. Melting Point
Answer: Ability to Burn
Explanation: I TOOK THE TEST
2. What is the formula to calculate speed?
Answer:
s=d/t
s=speed
d=distance traveled
t=time elapsed
If you weigh 118 lbs, how many kilograms is this
Answer:
the answer is 53.524 kg
A chemical reaction produces 56.2 grams of iron (II) sulfide (FeS). How many moles of iron (II) sulfide does the reaction produce? (1 mole FeS = 87.92 grams FeS) *
1.00 moles FeS
2.50 moles FeS
0.639 moles FeS
4.98 moles FeS
Answer:
0.639
Explanation:
If an element has atoms, in their ground-state, with 6 valence electrons, the element could be: (check all possible answers)
Answer:
You included no options however the elements with 6 Valence electrons are;
Oxygen ⇒ OSulfur ⇒ SSelenium ⇒ SeTellurium ⇒ TePolonium ⇒ Polivermorium ⇒ UuhValence electrons refer to the electrons an element has on its outermost shell. The number of these electrons determines the charge that an electron will carry as it seeks stability.
It also determines which group the element will be in in the Periodic table. Elements with 1 valence electron for instance will be in Group 1 and elements in Group 16 will have 6 valence electrons.
Write a balanced chemical equation for the standard formation reaction of gaseous hydrogen iodide
A balanced chemical equation for the standard formation reaction of gaseous hydrogen iodide is H₂(g) + I₂(g) → 2HI(g).
What is balanced reaction?Balanced chemical reactions are those in which equal amount of each entities will present on both sides of the reaction.
Formation of gaseous hydrogen iodide takes place by the mixing od hydrogen gas and iodine gas and balanced chemical equation for the formation of HI will be represented as:
H₂(g) + I₂(g) → 2HI(g)
So, required equation is H₂(g) + I₂(g) → 2HI(g).
To know more about balanced equations, visit the below link:
https://brainly.com/question/26694427
A chemist needs to create a series of standard Cu2+(aq) solutions for an absorbance experiment. For the first standard, he uses a pipet to transfer 10.00 mL of a 2.61 M Cu2+(aq) stock solution to a 250.0 mL volumetric flask, and he adds enough water to dilute to the mark. He then uses a second pipet to transfer 10.00 mL of the second solution to a 100.0 mL volumetric flask, and he adds enough water to dilute to the mark. Calculate the concentration of the Cu2+(aq) solution in the 100.0 mL volumetric flask. concentration: M
Answer:
0.01 M
Explanation:
The chemist is performing a serial dilution in order tyo obtain the calibration curve for the instrument.
First we must obtain the concentration of the solution in the 250ml flask from
C1V1 = C2V2
Where;
C1 = concentration of the stock solution
V1 = volume of the stock solution
C2 = concentration of the diluted solution
V2= volume of the diluted solution
2.61 × 10 = C2 × 250
C2 = 2.61 × 10/250
C2 = 0.1 M
Hence for solution in 100ml flask;
0.1 × 10 = C2 × 100
C2 = 0.1 × 10/100
C2 = 0.01 M
how many protons electrons and nuetrons does as have
The rate of reaction in terms of the "rate law expression" includes the rate constant (kk), the concentration of the reactants, and the orders of the reaction with respect to the different reactants. Consider the following reaction: A+B→C+DA+B→C+D The initial concentrations of the reactants AA and BB are 0.200 MM and 0.350 MM, respectively. The rate of reaction is 0.060 M⋅s−1M⋅s−1, and the orders of the reaction, with respect to reactants AA and BB, are 1 and 2, respectively. Determine the rate constant (kk) for the reaction using the rate law. Express your answer in M−2⋅s−1M−2⋅s−1 to three significant figures.
Answer:
[tex]k=2.45M^{-2}s^{-1}[/tex]
Explanation:
Hello.
In this case, considering the given specific orders of reaction, we can write the rate law as:
[tex]r=k[A][B]^2[/tex]
Thus, considering the concentrations of A and B to be 0.200 M and 0.350 M respectively and a rate of 0.060 M/s, the rate constant turns out:
[tex]k=\frac{r}{[A][B]^2}\\ \\k=\frac{0.060M/s}{(0.200M)(0.350M)^2} \\\\k=2.45M^{-2}s^{-1}[/tex]
This is what we know as a third-order reaction since the specific orders both add to 3.
Best regards.
pouring cold water in your hot coffee is
conduction
convection
radiation
Pouring cold water into your hot coffee is convection. Therefore, option B is correct.
What is convection?Convection can be explained as the transfer of heat from one place to another because of the movement of fluid. Convective heat transfer can be defined as the combined processes of conduction and advection.
Gases as well as liquids are not good conductors of heat under normal pressure and temperature conditions, but they can easily transfer heat from one region to another region.
Convection takes place through diffusion but does not take place in solids substances, as there is no movement of constituent particles takes place. The diffusion of heat energy that occurs in solids is called thermal conduction.
Heat energy transfer that takes place between a surface and a liquid when they come in contact with the surface is called convection heat transfer. Therefore, heat transfer takes place through convection when pouring cold water into hot coffee.
Learn more about convection, here:
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