Answer:
Phenolphthalein is an indicator. It is pink in alkaline solutions and turns colourless as the pH decreases.
It can be used to measure the activity of the enzyme lipase on the breakdown of lipids.
Samples of milk containing phenolphthalein were incubated with lipase at different temperatures.
The time taken for the phenolphthalein to turn colourless was recorded and used to calculate the rate of enzyme activity.
Figure 10 shows these results.
Picture
(a) (i) Explain why phenolphthalein turns colourless when lipase breaks down the lipids in milk. (2)
(ii) Describe the effect of temperature on the activity of lipase, as shown in Figure 10. (2)
(iii) Explain why the activity of lipase changes above a temperature of 40°C. (2)
(b) A student investigated the time taken for amylase to breakdown a 10% starch solution into glucose at 37°C. The student repeated the investigation five times.
Which best describes the current model of the atom?
O A a central nucleus containing protons with electrons orbiting in specific paths
O B. a solid sphere unique for everything that exists
O c a solid sphere with electrons and protons embedded
O D. a central nucleus containing protons and neutrons with electrons orbiting in levels of high probability
Explanation:
i think the answer might be D
Which of the following represents the chemical reaction of benzene and nitric acid to produce nitrobenzene and water?
Answer:
D
Explanation:
i mean it's just taking the words of the question and putting them into an equation
[tex]\huge\boxed{Option C}[/tex]
_____________________________________Equation:Benzene + Nitric Acid ---------> Nitrobenzene + water_____________________________________Explanation:As per Question,
It is saying that Benzene(organic compound) reacts with nitric acid. So,
Benzene and Nitric Acid are Reactants,
Nitrobenzene is the Product.
_________________________________________________________
General way of showing the reaction is,
Reactants --------> ProductIn the following Question,
Benzene is Reactant no. 1,
Nitric Acid is Reactant no.2,
Nitrobenzene is Product no 1,
Water is a By Product.
_____________________________________Best Regards,'Borz'Describe the ammonium ion, NH4+, and the sulfate ion, SO42-. What compounds would these ions form with potassium and fluoride ions? Write the formula units for the resulting compounds.
Explanation:
Ammonium Fluoride and Potassium Sulphate
What type of clothing would you need to wear if you could visit the mesosphere
The type of clothe that you would wear when visiting the mesosphere are the winter clothes.
What is mesosphere?Mesosphere is used to describe the coldest part of the earth whose temperature is -85°C.
An individual that wants to visit such a cold area should wear clothes that would provide such with warmth such as the winter clothes.
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A teacher showed this animal to students on a field trip which tool will allow the students to best see the animal up close
Answer:
Magnify glass
I WILL GIVE A LOT OF EXTRA POINTS. PLEASE ANSWER ALL OF THEM
75 for all
Explanation:
Answer:
Explanation: Li= Lithium, Na= Sodium, K= Pottasium, Rb= Rubdium Cs= Cesiuna, Fr= Fransium
6. Energy levels increases as if you move down a group during the number of electrons increases again.
7. A charge with higher and effective nuclear charge makes greater attractions to the electrons, pulling the electrons cloud closer to the nucleus makes it in a smaller atomic radius.
8. Ge= Germanium, He= Helium, O=Oxygen, Barium
What does it mean when there is a physical change?
Question 1 options:
A new substance has been formed.
Matter has changed size, shape or form.
Matter has changed from one substance into another.
Matter has changed on the molecular level.
Answer:
The matter has changed size, shape, or form.
Explanation:
A new substance that is formed is creation.
if the matter changed from one substance to another this is called a chemical reaction.
Surely not. It won't change the molecular level.
Hope that helps.
How could you explain why soap is able to clean the oil and dirt off your bodies?
Answer:
When you wash your hands with soap, it dislodges the dirt, grease, oils, and disease-ridden fecal matter particles on your hands by creating these micelles. Surrounded by the soap, the oil molecules become suspended and distributed in the water rather than stubbornly clinging to your skin.
Explanation:
When an aluminum atom becomes an ion, what is its charge?
Answer:
Initially, the aluminum atom had a charge of +13 + (−13) = 0; in other words, its charge was neutral due to the equal numbers of protons and electrons. When it becomes an ion, it loses 3 electrons, leaving behind only 10. Now the charge is +13 + (−10) = +3.
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How much energy would be required to heat 10.0 g of water at 0 degrees C to 100 degrees C,and change it into steam at 100 degrees C
Answer:
Q = 4180 J
Explanation:
Given data:
Mass of water = 10.0 g
Initial temperature = 0°C
Final temperature = 100°C
Heat required = ?
Solution:
Specific heat capacity of water is 4.18 j/g.°C.
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
ΔT = 100°C - 0°C
ΔT = 100°C
Q = 10.0 g ×4.18 j/g.°C × 100°C
Q = 4180 J
gasoline is separated from crude oil by heating it until it reaches it's boiling point. which separation method is used?
Answer:
Fractional distillation
Explanation:
The separation of gasoline from crude oil by heating until it reaches its boiling point is a separation technique called fractional distillation.
It is the separation of a mixture, such as crude oil into their respective fractions. This is achieved due to the differences in boiling point between the constituent fractions in the mixture. As the boiling point of a fraction is reached, it distills out from the column.how can animal fossils help us understand the earth
Answer:
Some animals and plant are only known to us as fossils. hope this helps. and have a nice day:)
Metal X displaces metal Y. Metal Z does not react with X or Y. What is the correct order of decreasing reactivity for metals X, Y, and Z?
Answer:
Metals on top of the activity series can displace metals at the bottom and they are highly reactive as compared to metals at the bottom of the series.
Hence, the order is X>W>Y>Z.
Please help!!! I can’t figure it out!
Answer:
The third answer
Explanation:
Which is heavier, calcium or selenium?
Answer:selenium
Explanation:
Answer: Nether
Explanation: Because if you have one pound of Calcium and one pound of selenium there both the same weight
How can we predict melting points?
Explanation:
Many of the properties of organic molecules can be predicted based on the strength of their cohesive molecule-molecule interactions (i.e. how much the molecules want to stick together). The boiling point (BP) and melting point (MP) of an organic molecule is related to: 1) the molecular weight of the molecule and 2) the "stickiness" of individual molecules for their neighbors.
For example, molecules in a liquid are held together by attractive interactions between molecules. These interactions must be broken (by adding heat) in order to transition into the gas. The stronger the cohesive interactions, the more heat that is necessary for the liquid-to-gas phase transition. These same attractive molecule-molecule interactions have to be broken for a solid to liquid phase change.
Examples: (Rank the following molecules in terms of MP and BP.)
Introduction to intermolecular forces:
All of the attractive intermolecular forces are based on the electrostatic attraction of positive charges on one molecule with negative changes. The stronger the charges, the stronger the attraction between molecules.
How to:
In general, comparisons can only be made between molecules with similar formulas or molecular weights.* First, identify the functional groups in the molecules being compared. Each functional group can form different types of intermolecular interactions (see the chart above). Interactions higher up on the chart form stronger cohesive interactions and will have higher boiling points and melting points.
* Note that larger molecules usually have higher boiling points and melting points. This is not because of their higher molecular weights but because they usually have greater surface areas with which to form more intermolecular interactions. This is also why linear molecules tend to have higher MPs and BPs than branched (or more spherically shaped) molecules. Linear molecules will have more surface area than a more spherically shaped molecule.
All three molecules have approximately the same molecular formula and molecular weights. Only molecule A contains a strongly polarized or ionic functional group: an aldehyde. The C=O group in aldehydes generate a strong molecular dipole (partial + and - charges). Thus, it can form weak attractive dipole-dipole interactions, and A will have the highest boiling point and highest melting point in this series of compounds.
Molecules B and C are alkanes. They can only form the weakest attractive dispersion interactions between their molecular surfaces. Due to its long-thin shape, B will have a greater surface area and can form more dispersion interactions than the rounder C. Therefore, B will have a higher boiling point and melting point than C.
Molecule A is ionic (it has charges). Therefore, it can form the strongest ion-ion interactions and will have the highest boiling point and melting point.
Molecule B is a carboxylic acid with an acidic proton and basic lone pairs. Therefore, it can form medium strength hydrogen bonding interactions, and it will have the next highest boiling point and melting point.
Molecule C is a carboxylic ester, which is a polar functional group. However, it does not have an acidic proton. Therefore, esters cannot form hydrogen bonds with themselves. Instead, they can only form weak dipole-dipole interactions and will have the lowest boiling point and melting point in this series of compounds.
Answer:
Explanation:
By thinking about non covalent intermolecular interactions, we can also predict relative melting points. All of the same principles apply: stronger intermolecular interactions result in a higher melting point.
Anita was using steel to make rusted sculptures. After building each sculpture, she caused the steel in the sculpture to rust by placing it into a tub filled
with salt water for eight hours. Anita wondered if steel would rust faster submerged in vinegar instead of salt water. To find out, Anita cut ten squares of
steel sheet metal and split them into two equal groups. She put one group of squares into a tub filled with salt water and the other group of squares
into a tub filled with vinegar. Once an hour for eight hours, Anita counted the number of rusted steel squares in each group.
What is the manipulated independent variable in Anita's experiment?
Answer:
The type of liquid in the tub (salt water or vinegar)
Explanation:
The manipulated independent variable in Anita's experiment is the type of liquid in the tub.
The independent variable is the controlled or manipulated variable in the course of an experiment. It can also be referred to as the 'cause' variable which has the capacity to produce 'effects' on another variable - the dependent variable.
In this case, the type of liquid the tub is filled (salt water or vinegar) will hypothetically affect the rusting period of the steel. Hence, the dependent variable is the type of liquid the tub is filled while the dependent variable would be the time it takes for the steel to get rusted.
Would it be possible for electrons in the 2p orbitals to be inside the 2s orbital?
(Please explain)
Answer:
Yes
Explanation:
You can have 2s and have part of the 2p of the row in the p section.
Un móvil se mueve con movimiento acelerado. En los segundo 2 y 3 los espacios recorridos son 90 y 120 m, Calcula la velocidad inicial y su aceleración
Answer:
La velocidad inicial es 55 [tex]\frac{m}{s}[/tex]y su aceleración es -10 [tex]\frac{m}{s^{2} }[/tex]
Explanation:
Un movimiento es rectilíneo uniformemente variado, cuando la trayectoria del móvil es una línea recta y su velocidad varia la misma cantidad en cada unidad de tiempo . Dicho de otra manera, este movimiento se caracteriza por una trayectoria que es una línea recta y la velocidad cambia su módulo de manera uniforme: aumenta o disminuye en la misma cantidad por cada unidad de tiempo. Y la aceleración es constante y no nula (diferente de cero).
En este caso la posición del objeto esta dada por la expresión:
[tex]x=x0+v0*t+\frac{1}{2} *a*t^{2}[/tex]
donde x es la posición del cuerpo en un instante dado, x0 la posición en el instante inicial, v0 la velocidad inicial y a la aceleración.
En este caso, por un lado podes considerar:
x= 90 mx0= 0 mv0= ?t= 2a= ?Reemplazando obtenes:
[tex]90=v0*2+\frac{1}{2} *a*2^{2}[/tex]
[tex]90=v0*2+\frac{1}{2} *a*4[/tex]
[tex]90=v0*2+2*a[/tex]
Y por otro lado tenes:
x= 120 mx0= 0v0= ?t= 3a= ?Reemplazando obtenes:
[tex]120=v0*3+\frac{1}{2} *a*3^{2}[/tex]
[tex]120=v0*3+\frac{1}{2} *a*9[/tex]
[tex]120=v0*3+\frac{9}{2} *a[/tex]
Por lo que tenes el siguiente sistema de ecuaciones:
[tex]\left \{ {{2*v0+2*a=90} \atop {3*v0+\frac{9}{2} *a=120}} \right.[/tex]
Resolviendo por el método de sustitución, que consiste en aislar en una ecuación una de las dos incógnitas para sustituirla en la otra ecuación, obtenes:
Despejando v0 de la primera ecuación:
[tex]v0= \frac{90-2*a}{2}[/tex]
Reemplazando en la segunda ecuación:
[tex]120=\frac{90-2*a}{2} *3+\frac{9}{2} *a[/tex]
Resolviendo:
[tex]120=(90-2*a)*\frac{3}{2} +\frac{9}{2} *a[/tex]
[tex]120=135-3*a +\frac{9}{2} *a[/tex]
[tex]120-135=-3*a +\frac{9}{2} *a[/tex]
[tex]-15=\frac{3}{2} *a[/tex]
[tex]\frac{-15}{\frac{3}{2} } =a[/tex]
-10=a
Reemplazando el valor de a en la expresión despejada anteriormente obtenes:
[tex]v0= \frac{90-2*(-10)}{2}[/tex]
Resolviendo:
[tex]v0= \frac{90+20}{2}[/tex]
[tex]v0= \frac{110}{2}[/tex]
v0=55
La velocidad inicial es 55 [tex]\frac{m}{s}[/tex]y su aceleración es -10 [tex]\frac{m}{s^{2} }[/tex]
Which of the following materials would probably be used as a conductor of electric current in a computer chip?
A rubber
B. glass
c. plastic
D. gold
Answer:
gold is metal which is a very good conductor for electric current and most chips are made out of it.
Answer:
The answer is D. gold
Explanation:
The chemical reaction for photosynthesis is: 6CO2 + 6H2O in sunlight yields C6H12O6 + 6O2. a. What is the function of sunlight in the reaction. b. What is the function of chlorophyll/ chloroplast?
Answer:
Sunlight provide light energy.
Chlorophyll absorb light.
Explanation:
Sunlight provide light energy or give light energy from sun and it is use to produce glucose from carbondioxide and water which is also a source of energy.
Chlorophyll absorbs light energy and use it to convert carbondioxide and water into glucose and oxygen or it captures sun rays and produce glucose and water.
water traveling in a circular motion when heating up a example of
A. Conduction
B. Convection
C. Radiation
D.none of these
Answer:
B.convection
Explanation:
Convection is the circular motion that happens when warmer air or liquid — which has faster-moving molecules, making it less dense — rises, while the cooler air or liquid drops down
Which of the following would be considered a derived unit? A) length B mass C) density D) temperature
Answer:
density because it S.I unit is derived from fundamentals
Which organic molecule is not considered a polymer? *
1 point
O nucleic acids
carbohydrates
O lipids
O proteins
Answer:
Lipids
Explanation: Lipids are, in fact, the only non-polymer organic molecules.
pb3(po4)2 compound name
Answer:
Lead phosphate
Explanation:
Pb3(po4)2 has the compounded name of lead(II) phosphate.
What is lead(II) phosphate like ?It is a white, crystalline solid that is insoluble in water. Lead(II) phosphate is used in some paints and plastics, and it is also used as a pigment.
The name of the compound is based on the oxidation state of the lead atom. Lead can have two oxidation states, +2 and +4. In Pb3(PO4)2, the lead atom has an oxidation state of +2, so the compound is named lead(II) phosphate.
The phosphate ion has an oxidation state of -3, so there are two phosphate ions in the compound to balance the +6 charge of the three lead atoms.
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Which properties change the composition of a substance?
chemical and physical properties
neither chemical nor physical properties
physical properties
chemical properties
GIVING BRAINLYYY
Use the general trends of the periodic table to answer the following question.
Platinum (Pt) and gold (Au) are sometimes called noble metals because they are less reactive than other metals. Based on this evidence and the periodic table, which other element is likely to be less reactive?
According to the electronic configuration, along with platinum and gold silver is considered to be a noble metal.
What is electronic configuration?
Electronic configuration is defined as the distribution of electrons which are present in an atom or molecule in atomic or molecular orbitals.It describes how each electron moves independently in an orbital.
Knowledge of electronic configuration is necessary for understanding the structure of periodic table.It helps in understanding the chemical properties of elements.
Elements undergo chemical reactions in order to achieve stability. Main group elements obey the octet rule in their electronic configuration while the transition elements follow the 18 electron rule. Noble elements have valence shell complete in ground state and hence are said to be stable.
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what is hard water and what causes hardness of water
Answer:
hard water is ice
Explanation:
ice is formed as the water temperature decreases and then it freezes
3
1. The observed regularities in the properties of
the elements are periodic functions of their
(1) atomic numbers
(2) mass numbers
(3) oxidation states
(4) nonvalence electrons
Answer:
(1) atomic numbers
Explanation:
The observed regularities in the properties of the elements on the periodic table are periodic functions of their atomic numbers.
Atomic number is the number of protons in an atom. The periodic law states that "the properties of elements are a periodic function of their atomic number".Elements on the periodic table are arranged based on the atomic numbers they contain. The number of positively charged particles in an atom is the atomic number.The observed regularities in the properties of the elements are periodic functions of their atomic numbers.
Modern periodic law states that "Properties of elements are a periodic function of their atomic number not by their atomic mass". Modern periodic law was proposed by Henry Moseley in 1913. Physical and chemical properties of elements depend on the number of electrons and their arrangement.
Thus properties of elements are periodic function of their atomic numbers and not atomic masses. If the properties of an element depend on number of proton and neutron then the properties are periodic function of their atomic mass so we can conclude that the observed regularities in the properties of the elements are periodic functions of their atomic numbers.
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