please help me with this
Answer:
47. C
48. d
49. a
50. b
51. e
52. c
53. c
54. a
55. b
Explanation:
Did school teach you a lot?
Did school make your life better??
Did school make you happy?
I just wanted a other opinion
Answer: it definitely did help me a lot but sometimes it doesn’t make me happy like i will get stressed but it passes.
Explanation:
What does the photoelectric effect show about the properties of light?
Answer:
The photoelectric effect proves that light has particle-like activity,The photoelectric effect happens when photons are shone on metal and electrons are ejected from the surface of that metal.
Explanation:
How much is the oxygen valency?
How much aluminum can be extracted from 3.5 metric tons of bauxite ore which is 70% aluminum oxide?
Answer:
A) 17.5%
B) 1) 2135 kg
2) 375 kg
C) 91.8
Explanation:
Part (A):
1 tonne= 1000 kg= 100%
Aluminium oxide= 825 kg= 82.5%
Iron (lll) oxide= 100 kg= 10%
Sand= 85 kg= 7.5%
That makes total of 100%
So, the percentage of impurities= Iron (lll) oxide + Sand
=> 10 + 7.5= 17.5%
Part (B):
(1) 1 tonne= 427 kg
Multiplying both sides by 5
=> 5 tonne= 427 * 5
=> 5 tonne = 2135 kg
(2) 1 tonne contains 75 kg sand as impurity
=> 1 tonne= 75 kg
Multiplying both sides by 5
=> 5 tonnes = 75 * 5
=> 5 tonnes = 375 kg
Part (C):
If all of the iron oxide was removed, then only aluminium and sand are left.
Aluminium = 825 kg
Sand= 74 kg
Total of them makes it:
=> 825 + 74 = 899
So,
% age of Aluminium= 825/899 * 100
% age of Aluminium= 0.918 * 100%
% age of Aluminium= 91.8%
why do atmospheric carbon dioxide levels fluctuate during the year?
Answer: The amount of CO2 found in the atmosphere varies over the course of a year. Much of this variation happens because of the role of plants in the carbon cycle
explain why it is necessary to change models as new information becomes available.
Answer:
Scientific models are not a replacement for experimentation. They can be used in conjunction with experimentation to further understanding of a concept, event, or process. They are based on current scientific knowledge and may have to be changed when new discoveries are made.
Explanation:
that's my answer
#carryonlearning
Which of the following solutions represents a good buffer system? a solution that is 0. 10 mol L-1 HF and 0. 10 mol L-1 CH3COONa a solution that is 0. 10 mol L-1 HCl and 0. 10 mol L-1 NH4 a solution that is 0. 10 mol L-1 CH3COOH and 0. 10 mol L-1 CH3COOLi a solution that is 0. 10 mol L-1 NaOH and 0. 10 mol L-1 KOH a solution that is 0. 10 mol L-1 HCl and 0. 10 mol L-1 KCl.
Answer:
first
Explanation:
0. 10 mol L-1 HF and 0. 10 mol L-1 CH3COONa a solution that is 0 is a good buffer system. so, option A is correct.
What is buffer system ?When acids or bases are introduced, a buffer system is a solution that resists changing in pH. Acidic solutions have pH values under seven and significant hydrogen ion ( H+ ) concentrations. Basic solutions have pH values higher than seven and high quantities of hydroxide ions ( OH- ).
The carbonate, carbonic acid buffer, the phosphate buffer, and the buffering of plasma proteins make up the body's chemical buffer system.
Plasma proteins, phosphate, bicarbonate, and carbonic acid buffers are among the buffer systems active in blood plasma. By excreting hydrogen ions and producing bicarbonate, which helps keep blood plasma pH within a normal range, the kidneys contribute to the regulation of acid-base balance.
Thus, option A is correct.
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diagram of paper chromatography from a chemistry textbook
3. Elements in the s and p blocks of the periodic table are called
a. alloys.
b. main-group elements.
C. metals.
d. transition metals.
Answer:
The answer is B: main-group elements.
Explanation:
Answer:
b
Explanation:
What types of bonds, and how many bonds, do you predict arsenic form with other elements?
Answer:
The outer-shell similarity of the two elements suggests that arsenic, like phosphorus, can form three covalent bonds per atom, with an additional lone pair of electrons left unbonded.
Atomic number: 96
Oxidation states: +3, +4
Arsenic atom can form either three or five bonds in arsenic compounds.
The number of bonds that an element will form to other elements depends on the number of electrons on the valence shell of that element. Arsenic has five valence electrons on its valence shell.We know that there is one lone pair on the valence shell of arsenic hence, the arsenic atom can form either three or five bonds in arsenic compounds.In conclusion, arsenic is an element that could form three or five bonds in its compounds.
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What is the relative molecular mass, Mr, of butanol, C4H9OH
A- 15
B- 37
C- 74
D- 148
Answer:
C-74
Explanation:
carbon is 12 the hydrogen is 1 andthe oxygen is 16/-this is molecular mass for each element
the just follow the molecular formula and sub the valu
you sould be getting 74 ok
hope u understand
A chemical reaction resulting in the transfer of electrons or hydrogen atoms from one molecule to another is called a(n) _______ reaction.
Answer:
Explanation:
Oxidation reaction
The kind of reaction involving the transfer of electrons or hydrogen away from a molecule is called oxidation.
In the same vein, the molecule that receives the electron or the hydrogen atom is said to be reduced. This means that oxidation cannot exist in isolation without reduction.
In other words, oxidation is defined as:
Loss of electronsLoss of hydrogen atomsGain of oxygen atomsGain in oxidation numberWhile reduction is defined as:
Gain of electronsGain of hydrogen atomLoss of oxygen atomReduction in oxidation numberMore on oxidation/reduction reactions can be found here: https://brainly.com/question/3867774
NO ONE IS ANSWERING PLS HELP!
Which product in the reaction forms a precipitate?
AgCl
AgK
No precipitate formed
Answer:
AgCl
Explanation:
Got correct on E2020
Answer:
B: AgCl
Source: trust me bro
What mass will 33.6 L of chlorine gas (Cl2) have at STP?
A.) 35 g
B.) 53 g
C.) 71 g
D.) 106 g
1. The heat of combustion is a negative value. Do you think this indicates an exothermic or endothermic reaction? Explain.
Answer:
Exothermic
Explanation:
Combustion reactions are almost always exothermic because it is an oxidation reaction that produces heat and in this case it would be considered to be exothermic but there are few cases in which it would be considered endothermic. Combustion of Nitrogen is endothermic because Δ is positive despite being a combustion reaction.
Rocks and fossils leave evidence of the conditions that were present when they formed.
true of false
What is moisture in the atmosphere
Answer: MOISTURE IN THE ATMOSPHERE, in the form of water vapor, liquid water, and ice, controls most aspects of our weather and climate. ... Atmospheric moisture is expressed as clouds, precipitation, storms, weather fronts, and other phenomena.
can the following alcohol be prepared as a single product by hydroboration-oxidation of an alkene? can it be prepared as a single product by the acid-catalyzed addition of h2o to an alkene? select the single best answer.
Answer:
Yes both methods give a single product.
Explanation:
The answer can be Yes, both the methods will yield a single product. The correct option is D.
What is alcohol formation?Alcohols can be made by hydrating alkenes or reducing aldehydes, ketones, acids, and esters. Water elements can be added to an alkene's doublebonded carbons in either a Markovnikov's or an antiMarkovnikov's manner.
When yeast ferments the sugars in grains, fruits, and vegetables, it produces it. For example, wine is made from grape sugar, and vodka is made from potato sugar.
In the presence of a catalyst, lower molecular weight olefins react with carbon monoxide and hydrogen in a reaction known as hydroformylation or the oxo reaction. The resulting aldehyde is then hydrogenated to produce alcohol.
Thus, the correct option is D.
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Your question seems incomplete, the probable complete question is attached below:
How many total atoms of Nitrogen are shown in the formula below?
4N₂O
2
4
6
8
Answer:
8
EXPLANATION hope this helps you
Answer:8
Explanation:
Pls help me!! Explain how the N:Z ratio can help predict the type of radiation Zr-85 and Zr-95 emit.
No links pls
Based on N:Z ratio, Zr-85 is expected to decay by positron emission. Zr-95 is expected to emit beta particles in a beta decay.
The N:Z ratio determines the stability of a nucleus. If a nucleus has N:Z ratio >1.5 or <1.0, such a nucleus is unstable and will undergo radioactive decay. The aim of such a decay is to attain a favorable N:Z ratio.
For Zr -85, the N:Z ratio is 1.1 while the N:Z ratio of Zr-95 is 1.4. Zr -85 is expected to decay by positron emission which increases the N:Z ratio. For Zr-95, the nucleus tends to undergo processes that decrease the N:Z ratio such as beta emission.
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(Total for Question 3-5 marks)
Q4. Carbon monoxide and hydrogen are used in the manufacture of methanol (CH3OH)
The reaction is reversible and can reach a position of dynamic equilibrium.
CO(g) + 2H, (g) = CH OHg) AH = -91 kJ/mol
The reaction is carried out at a pressure of about 100 atmospheres and a temperature of 250°C.
(a) State two features of a reaction that is in dynamic equilibrium.
1
2
Page 9 of 11
Answer:
1. Forward and Backward reaction rate are equal
2. Concentration of reactants and products are the same.
what is solubility?
Answer:
the ability to be dissolved, especially in water.
Explanation:
how is the mode of data set defined
it is the middle value of the set
Answer:
No, mode isnt the middle value of a set that is median.
Explanation:
Mode (also known as modal class) is the value that appears most frequently in a data set.
The relative atomic mass of chlorine is 35.5.
When calculating relative atomic mass, which particle is the mass of a chlorine atom compared
to?
Given what we know, we can confirm that relative atomic mass is calculated by comparing the particles to the atomic mass of a carbon-12 atom.
Why compare to carbon-12?Carbon is a very common element. It was been studied greatly, telling us a great deal about the atom. It contains 6 protons and 6 neutrons.This makes it very stable and the standard for comparison.Therefore, given its abundant nature and the fact that it has been extensively studied, we can confirm that a carbon 12 atom has exactly 6 protons and 6 neutrons, making it very stable and the standard to which other atoms are compared.
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Which does ionic bonding involve?
Describe how the temperature change suggests a chemical change occurred?
NO LINKS PLEASE
Answer:
When energy is either absorbed or released, it is indicative of a chemical change. Fireworks are an example of a chemical change that produces a temperature change and emits light.
A watch loses 0.15 sec/min, how many seconds are lost in 24 hours?
Answer:
0.15 sec/min = 9 sec/hour
9*24 = 216 seconds = 3.6 minutes
Explanation:
Answer:
216 Seconds
Explanation:
If every minute is 60 seconds than 60 multiplied by .15 is 9 Seconds Lost.
If every hour is 60 minutes compared to what we know than 24 hours multiplied by 60 is 1440 minutes.
Do the same math as before: 1440 x .15 = 216 Seconds
What is the density of a bowling ball with a mass of 3.0 kg and a volume of 0.0050 m 3 ?
0.002 kg/m 3
0.015 kg/m 3
500 kg/m 3
600 kg/m 3
Answer:
600 kg/m³
Explanation:Formula to used = m/v
[] d is the density
[] m is the mass
[] v is the volume
Solving[Formula] d = m/v
[Plug-in] d = 3/0.0050
[Divide] d = 600 kg/m³
Answer0.002 kg/m³
0.015 kg/m³
500 kg/m³
600 kg/m³
Have a nice day!
I hope this is what you are looking for, but if not - comment! I will edit and update my answer accordingly. (ノ^∇^)
- Heather
Answer:
[tex]\boxed {\boxed {\sf 600 \ kg/m^3}}[/tex]
Explanation:
We are asked to find the density of a bowling ball. The density of an object is its mass per unit volume. It is calculated by dividing the mass by the volume.
[tex]\rho= \frac{m}{v}[/tex]
The mass of the bowling ball is 3.0 kilograms and the volume is 0.0050 cubic meters.
m= 3.0 kg v= 0.0050 m³Substitute the values into the formula.
[tex]\rho= \frac{3.0 \ kg}{0.0050 \ m^3}[/tex]
Divide.
[tex]\rho= 600 \ kg/m^3[/tex]
The density of the bowling ball is 600 kilograms per cubic meter.
Early in Earth's history there were more volcanic eruptions and meteorite impacts than there are today.
Question 3 options:
True
False
Answer:
True
Explanation:
Volcanic eruptions and meteorite impacts were way more common back when the Earth was newly formed.