Answer:
This law states that, despite chemical reactions or physical transformations, mass is conserved — that is, it cannot be created or destroyed — within an isolated system. In other words, in a chemical reaction, the mass of the products will always be equal to the mass of the reactants.
A substance melting on the stove
is an example of a chemical
change
True
b. Flase
a.
Answer:
A. True hope this helped
Craik and Lockhart (1972) proposed the idea that deeper levels of ____ results in stronger retention of memories
A. Rehearsal
B. Multitasking
C. Memory
D. Processing
Answer: D. Processing
Explanation: 100% on topic test also its in my e notes.
Craik and Lockhart has proposed theory of memory processing. Thus, option D is correct.
Craik and Lockhart proposed the theory for the processing of the level of memory. The memory in humans can be sensory memory, working memory, and long-term memory.
The long term memories have been stored in the deeper cells and the increased or strong stimulation of the processing results in the stronger retention of the memories. Thus, option D is correct.
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A student estimated a mass to be 275 g but upon carefully measuring it found the actual mass to be 260 g. what is the percent error in the estimation?
Answer:
5.77% Error.
Explanation:
Given an experimental value of 275 g , and a theoretical value of 260 g, the percent error can be found using the equation:
[tex]\% \: error \: = \frac{ |theoretical \: value \: - \: experimental \: value | }{theoretical \: value} \times 100[/tex]
% Error = ( | 260 - 275 | / 260 ) × 100 = ( | - 15 | / 260 ) × 100 = ( 15 / 260 ) × 100 = 1500/260 = 300 / 52 = 5.769230769230.. ≈ 5.77%
A researcher wants to refine an investigation to determine the effectiveness of an enzyme at various temperatures. Which of the following would best help the researcher determine how well the enzyme is working? Question 20 options: The researcher should measure the difference in temperature during the reaction. The researcher should measure the difference in the amount of product at the beginning of the reaction. The researcher should measure the difference in the amount of enzyme remaining after the reaction. The researcher should measure the difference in the amount of product at the end of the reaction.
Answer:
The researcher should measure the difference in the amount of product at the end of the reaction.
Explanation:
Enzymes are defined as the protiens that are responsible for increasing the rate of reaction.
With the increase in temperature, the enzyme activity increases and so the rate of reaction increases. It means at lower temperature the rate of reaction decreases and the amount of product also decreases.
So, to determine the effectiveness of an enzyme at various temperatures, the difference in the amount of the product at the end of reaction should be measured.
Hence, the correct answer is "D".
You have a different rock with a volume of 30cm and a mass of 60g, What is its density?
what is the molar mass of CO^2
Answer:
44.01 g/mol
There you go, hope it helped!!!!!
What is an experimental error
Answer:
Explanation: errors in judgment of an observer when reading the scale of a measuring device to the smallest division. 2. Environmental. For example, unpredictable fluctuations in line voltage, temperature, or mechanical vibrations of equipment.
A different student is given a 10.0g sample labeled CaBr2 that may contain an inert (non-reacting) impurity. Identify a quantity from the results of laboratory analysis that the student could use to determine whether the sample was pure.
Answer:
Melting Point.
Explanation:
In testing of a sample has impurities, we have to check the samples’s melting or boiling points or we a separation technique called chromatography.
Now, CaBr_2 which is calcium bromide is a White Hygroscopic Powder. Therefore it is a solid.
Now, a pure solid will always have a fixed melting point which means that it will melt completely at only one temperature.
However, if there are impurities, the melting point of a substance is affected in two ways:
-It's lower than than the fixed melting point
- It would melt at a range of different temperatures as opposed to a fixed temperature for the pure form.
Therefore, a quantity that can be used to determine whether the sample was pure will be melting point.
Which phrase is the best definition of science?
Answer:
Science is the information gathered through study.
Explanation:
Answer:Observation of the physical world.
Explanation:
Choose the nonmetallic elements from the list. Check all that apply yttrium: oxygen: boron: polonium: argon: gallium: carbon:
Answer:
Oxygen, Argon, and Carbon.
Explanation:
Just finished the assignment.
Oxygen ,boron and carbon are the non metallic elements. Thus, options B, C, and G are correct.
What are non metallic elements?Non-metallic elements are the elements which easily form negative ions by accepting or gaining electrons and which do not have complete electronic configuration like rare gas. Non metals have high ionization energies and electronegativity.
They are generally poor conductors of heat and electricity. Solid non metals are generally brittle, with little or no metallic lustre.
Most non metals have the ability to gain electrons easily. Non metals display a wide range of chemical properties and reactivities.
In above except oxygen, boron and carbon all other elements are metallic in character that possess metallic property. Thus, options B, C, and G are correct.
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Which image below shows the correct way to convert 0.828 kilometers to meters
Explain the rationale and what happens to the units.
Answer:
A
Explanation:
Because you need to multiply the length value by 1000
is helium gas a mixture or pure substance
What is the speed of an object that moves 100 meters in 5 seconds?
Answer:
speed= distance/time
= 100/5=20mph
During respiration, energy is retrieved from the high-energy bonds found in certain organic molecules. Which of the following, in addition to energy, are the ultimate products of respiration?
(a) CO2, H2O
(b) CH3, H2O
(c) CH2OH, O2
(d) CO2, O2
Answer:
(A.) CO2, H2O
Explanation:
The chemical equation for respiration process is:
[tex]C_{6}H_{12} O_{6}[/tex] + [tex]6O_{2}[/tex] → [tex]6CO_{2}[/tex] + [tex]6H_{2} O[/tex] + ATP↑
Energy is released during the biochemical process in the organism's cells in form of ATP. Byproducts of the reaction are carbon dioxide and water molecules.
Let me know if you require any further assistance.
DNA is a double stranded molecule. If one strand is ATCGATCGATCG, what is the sequence of the other strand?
Variable definition
Answer: is factor that change in a controlled experiment
Explanation:
A class is 47 min how many seconds is this ?
Answer: 2820 seconds
1 minute = 60 seconds
Multiply the value times 60
47×60=2820
Describe how the proton, electron and neutron were experimentally discovered.
If the pressure, volume, and the number of moles of a gas are known, which is needed to calculate the universal gas
constant from the ideal gas laul?
O the temperature of the gas
the molar volume of the gas
the molar mass of the gas
the partial pressure of the gas
Explanation:
temperature of the gas
how many seconds are there in 45 days?
Answer:3,888,000seconds
Explanation:
60secx60minsx24 hoursx45days=3,888,000
What does the mass of an object depend on?
A. Force of gravity
B. Temperature of the object
C. Time taken of an event to occur
C. Amount of matter that makes up the object
Answer:
D or the 4th one
Explanation:
mass is literally the measure of matter in an object which is essentially the weight or how much stuff there is.
Answer:
C:)
Explanation:
Which statement describes the general process of diffusion?
Molecules move from inside of the cell to outside of the cell.
Molecules start out unevenly distributed and end up evenly distributed.
Molecules start out evenly distributed and end up unevenly distributed.
Molecules move from outside of the cell to inside of the cell.
Answer:
Molecules start out unevenly distributed and end up evenly distributed.
Explanation:
Diffusion is the process by which molecules of a substance move from a region of higher concentration to a region of lower concentration until equilibrium is attained.
Molecules start out unevenly distributed and end up evenly distributed in a particular medium. Diffusion occurs due to the particulate nature of matter. When the particles that make up a substance are concentrated at a point, the collide more often with one another causing each molecule to spread out in order to occupy all the available space.
Diffusion occurs in gases, liquids and solids but occurs fastest in gases. Diffusion can be observed for example, in the spread of the smell of a dead rat from one point in a room to every part of the room.
Answer:
B
Explanation:
:D
What occurs when a solid substance dissolves into a liquid? 1 It stays solid and sinks to the bottom of the liquid substance. 2 It breaks down and becomes part of the liquid substance. 3 It stays solid and floats on the top of the liquid substance. 4 It changes the liquid substance into a solid substance.
Explanation:
When a solid substance is dissolved in a liquid such as water, the intermolecular forces of attraction between the molecules in the solid substance are overcome and they exist as ions in the solution. Hence the answer is 2.
The correct option is 2.
When a solid substance is dissolved in a liquid such as water, the intermolecular forces of attraction between the molecules in the solid substance are overcome and they exist as ions in the solution.
What is dissolution?Dissolution is the process in which a substance forms a solution. Dissolution testing measures the extent and rate of solution formation from a dosage form, such as a tablet, capsule, ointment, etc. The dissolution of a drug is important for its bioavailability and therapeutic effectiveness.
What is an example of a dissolution?Stirring sugar into water is an example of dissolving. The sugar is the solute, while the water is the solvent. Dissolving salt in water is an example of the dissolution of an ionic compound.
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Which of the following is a property of a pure substance?
It consists of different types of compounds.
It may have substances in different states of matter.
The ratio of the particles that make it up is fixed.
Its components can be separated by employing physical methods.
Answer:
The ratio of the particles that make it up is fixed
Explanation:
what is the most poisonous animal?
Answer:
That depends on what species it is
Explanation:
Like reptiles it is rattlesnakes
Spiders would be black widow
So it depends on the what species you what.
Which chemistry is used to create energy? *
Nuclear Chemistry
Organic Chemistry
Analytical Chemistry
Biochemistry
Answer:
*biochemistry* is the answer
Answer:
No the real answer is nuclear chemistry
Explanation:
120mg=______g please help
Answer:
0.12
Explanation:
Cuz you divide the mass value by 1000.
Much Smort (I look up on internet)
. The freezing point of an aqueous solution containing a nonelectrolyte solute is – 2.79 °C. What is the boiling point of this solution?
Answer:
Boiling point of the solution is 100.78°C
Explanation:
This is about colligative properties.
First of all, we need to calculate molality from the freezing point depression.
ΔT = Kf . m . i
As the solute is nonelectrolyte, i = 1
0°C - (-2.79°C) = 1.86 °C/m . m . 1
2.79°C / 1.86 m/°C = 1.5 m
Now, we go to the boiling point elevation
ΔT = Kb . m . i
Final T° - 100°C = 0.52 °C/m . 1.5m . 1
Final T° = 0.52 °C/m . 1.5m . 1 + 100°C → 100.78°C
2. A golden-colored cube is handed to you. The person wants you to buy it for
$100, saying that it's a gold nugget. You pull out your old geology text and
look up gold in the mineral table, and read that its density is 19.3 g/cm3. You
measure the cube and find that it is 2 cm on each side, and has a mass of 40g.
What is its density? Is it gold? Should you buy it?
Answer:
Volume of the cube is 2*2*2 = 8cm^3.
Divide the weight (40g) over the volume (8cm^3).
Density is 5g/cm^3. Definitely not gold.
Explanation:
Yes, the given golden-colored cube is gold .The density of gold is 32 gm/cm³ and we must buy it.
What do you mean by density?Density is a mass of a unit volume of a material substance.
The formula for density is d = M/V, where d is density, M is mass, and V is volume.
Density is commonly expressed in units of grams per cubic centimetre.
To calculate density-
given
mass=40gm
side of cube =2cm
therefore, volume=(side)³
=8cm³
density=?
density=mass/volume
density=40/8
density=5 gm/cm³
The handed golden-colored cube is gold with its density 5gm/cm³ and hence we must buy it.
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Use the table to identify the phase and phase changes of the elements under the given conditions. Write the name of the substance, phase, or phase change.
When the temperature in a room increases from
25°C to 33°C,
changes from a solid
to a liquid.
In a lab, methane and nitrogen are cooled from
-170°C to -200°C. The methane freezes and the
nitrogen
.
When gold is heated to 2,856°C it changes from a liquid to a
.
Answer: gallium, condenses, gas
Explanation: took assignment on edge
Answer: gallium, condenses, gas
Explanation: took assignment on edge