physical changes are those changes which can be reversed in their previous form like ice to water
chemical changes are those changes which cannot be reversed in their previous form
1. the change which are reversable are known as physical change
2.no new substance are formed
3.no change in chemical nature of the substance
4. example: • melting of ice
• tearing of paper etc.
chemical change:1.this are irreversible this can't be reverse
2.new substance are formed
3.it results form a chemical reaction
4. example: • burning of wood
• rusting of iron etc.
hope it helps you :)
What year did Canada switch to the metric system?
Answer:
1970
Explanation:
1970, Canada gradually began to convert from an imperial to a metric system of measurement
Does riding a bike with larger tires help you go faster even if you pedal at the same rate A:if the person moves faster, then the person is riding a bike with larger tires B: if a person rides a bike with larger tires ,then the person with move faster than on a bike with smaller tires
Answer:
Yes, bikes with larger tires help you go faster.
B: if a person rides a bike with larger tires ,then the person with move faster than on a bike with smaller tires
Explanation:
Bikes with larger wheels cover more distances in one revolution, when compared to bikes with a much smaller wheel, if the wheels are turning at the same revolution per minutes. Although more effort is put into turning a big wheel, when compared to that for a smaller wheel, but it will go faster if you can keep it spinning at the same rate as a small one.
Balance the equation : CH3COOH(aq) + NaHCO3(s) -> CO2(g) + H2O(l) + Na+(aq) + CH3COO-(aq) and provide an explanation
Answer:
Explanation:
CH₃COOH(aq) + NaHCO₃(s) -> CO₂(g) + H₂O(l) + Na+(aq) + CH₃COO-(aq)
The equation is already balanced .
In the reaction acetic acid reacts with sodium bicarbonate to produce carbon dioxide gas , water and sodium acetate . Sodium acetate will be in ionic form ie in the form of Na⁺ ( sodium ion ) and CH₃COO ⁻ ion ( acetate ion ) .
This is an acid base neutralisation reaction . one mole of acetic acid reacts with one mole of sodium bicarbonate to produce one mole of carbon dioxide gas , one mole of water and one mole of sodium acetate in ionic form .
Where is the mass of an atom found? Explain.
Explanation:
Over 99.9% percent of an atom's mass resides in the nucleus. The protons and neutrons in the center of the atom are about 2000 times heavier than the electrons orbiting around it.
Because the electrons are so light by comparison,they represent only a tiny fraction of a percent of the atom's total weight.
Hope this answer helps you!
a sample of an unknown liquid has a volume of 24.0 mL and a mass of 6 g.what is its density?
Answer:
Density=mass / volume.
Density=6×24=144g/cm^3.
Answer:
0.25 g/mL
Explanation:
Density = mass/volume
Volume = 24.0 mL
Mass = 6 grams
Density = 6 grams/24.0 mL
Density = 0.25 grams/mL
An organic chemistry student is experimentally determining the
melting point of fluorenone. The experimental melting points are
listed below from a to e. Which one should he discard so that he
can say his data is precise?
a 83.5 °C
b 85.6 °C
C 83.6 °C
d 83.4 °C
e 83.3 °C
Answer:
85.6 °C
Explanation:
Precision in scientific measurements refers to how close together the results of a repeated scientific measurement is. In this particular case where the melting point of fluorenone is being determined, precision refers to how close together the values from repeated measurements of the melting point of fluorenone is.
If we look at the values, the only one that is not close to others is 85.6 °C. Hence, if we remove this particular value, the data can be regarded as being precise.
Answer:
its C
Explanation:
how i know is did it on a piece of paper and got C for the answer. Have a nice day!
Convert 550 Hm to mm
Answer:
55,000,000
Explanation:
550 hectometers [hm] = 55,000,000 millimeters [mm]
. Name something chemistry related you are interested in or interested in learning about.
Answer: How The World Works
Explanation: Our world is made out of atoms, molecules and ions. Their behavior determines the properties of the substances we encounter in our daily lives: their structure, color, smell, and the way they interact with each other.
A lab group was measuring the mass of an object. They recorded the following masses for the same object: 12.13 g, 12.12 g, 12.13 g, and 12.11 g. The actual mass of the object was 17.13 g. Which of the following best describes the lab groups results? The results were both accurate and precise. The results were accurate but not precise. The results were precise but not accurate. The results lacked both precision and accuracy.
Answer:
Precise, but not accurate
Explanation:
First, let’s define accuracy and precision.
⇒Accuracy: how close you are to the actual value
⇒Precision: how close the measurements are to each other.
Let’s examine the data given:
12.13 g, 12.12 g, 12.13 g, and 12.11 g
Each number is or is very close to 12.12 (within 0.1)
The actual mass of the object is 17.13 grams. Each measurement is about 5 grams away from the actual mass.
Since the measurements are very close to each other, but quite far from the true value, we can say the results are precise, but not accurate.
Explain which is the better coolant: water or methanol?
Answer:
Water
Explanation:
Because it has a higher specific heat capacity.
Water is a better coolant than methanol due to its high specific heat capacity.
The specific heat is the amount of heat per unit mass required to raise the temperature by one degree Celsius.
It is a measure of how much energy it takes to raise the temperature of a substance. It is the amount of heat necessary to raise one mass unit of that substance by one temperature unit.
Methanol effective in preventing the coolant from freezing, its low boiling point and low specific heat capacity led to considerably less cooling than water alone. Also, the concentration of methanol would tend to be reduced over time due to its greater tendency to evaporate than the water with which it was mixed.
Learn more about Specific heat, here:
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What is the average yearly rate of change of carbon-14 during the first 5000 years?
Answer:
The average yearly rate of change of carbon-14 during the first 5000 years = 0.0004538 grams per year
Explanation:
Given that the mass of the carbon 14 at the start = 5 gram
At the end of 5,000 years we will have;
[tex]A = A_0 \times e^{-\lambda \times t}[/tex]
Where
A = The amount of carbon 14 left
A₀ = The starting amount of carbon 14
e = Constant = 2.71828
[tex]T_{1/2}[/tex] = The half life
[tex]\lambda = 0.693/T_{1/2}[/tex]
t = The time elapsed = 5000 years
λ = 0.693/[tex]T_{1/2}[/tex] = 0.693/5730 = 0.0001209424
Therefore;
A = 5 × e^(-0.0001209424×5000) = 2.7312 grams
Therefore, the amount of carbon 14 decayed in the 5000 years is the difference in mass between the starting amount and the amount left
The amount of carbon 14 decayed = 5 - 2.7312 = 2.2688 grams
The average yearly rate of change of carbon-14 during the first 5000 years is therefore;
2.2688 grams/(5000 years) = 0.0004538 grams per year
The average yearly rate of change of carbon-14 during the first 5000 years = 0.0004538 grams per year.
help pls i need help and i’m tired i took 15 test today-
Answer:
3
Explanation:
Lithium's atomic number is 3. it has 3 protons in its model
Significant Figures - write the number of significant figures in the blank.
______ 1. 53
______ 2. 53.0
______ 3. 0.053
______ 4. 0.0503
______ 5. 530
______ 6. 530.
______ 7. 530.0
______ 8. 5030
______ 9. 5030.
______ 10. 5030.001
______ 11. 5-300.001
The label on a soft drink bottle gives the volume in two units: 2.0 L and 67.6 fl oz. Use this information to derive a conversion factor between the English and metric units. How many significant figures can you justify in your conversion factor?
Answer:
Explanation:
The significant figures are determined by 2.0. It only has 2 places, so the answer to the last question is 2.
The English unit is 67.6 oz
The metric unit is 2 L
So there are 67.6 fl oz / 2 L = 33.8 fl oz / L
In other words 1 liter has 33.8 fl oz
But you only have 2 sig digs so the answer is actually 34 fl oz/L
What period is the atom in?
What group is the atom in?
What is the name of this atom?
What other atom would have similar properties
to the atom?
Would this atom be malleable or brittle?
The kinetic engery of molecules increase as you go from solid liquid gas true or false
Bob walks 81m East and then he walks 103m West.
The Answer your looking for is
He walked the distance of: = 184 m
Wind erosion
ER
O removes the fertile B horizon of soil
o can be reduced by cutting down trees
O happens slowly in dry climates
en in de
is both destructive and constructive
Answer:
removes the fertile B horizon of soil
Explanation:
Wind erosion has the capacity to remove the fertile B horizon of the soil.
The term wind erosion generally refers to the capacity of high-magnitude wind to cause damages to the terrestrial environment. Soils can get their topmost layers removed by a strong wind if there are no barriers such as vegetation to break the speed of the wind.
The topmost layers in most cases consist of humus and the fertile minerals from parent materials. When the topmost layer is lost, the soil becomes unproductive for agriculture.
What is an isotope?
о
an atom that has gained electrons
O
an atom that has lost electrons
O
two or more forms of an atom that contain different numbers of neutrons
O
two or more forms of an atom that contain different numbers of protons
Answer:The answer is C:two or more forms of an atom that contain different numbers of neutrons. An isotope is when there are different forms of an atom, in terms of neutrons. Not to be confused with cations or anions, which are atoms with a difference of electrons or protons, making them charged.
Explanation: I took chemistry in 6th grade.
A drug is administered at a rate of 13.5 cL/hour. What is this rate in µL/s?
Answer:
A drug administered at a rate of 13.5 cL/hour has a rate in μL/s of 37.5 μL/s
Explanation:
The given rate at which the blood is administered = 13.5 cL/hour
The rate at which the question asked to be administered = μL/s
The conversion factor between cL and μL is given as follows;
1 cL = 10,000 μL
Which gives;
13.5 cL/hour × 10,000 μL/cL × 1 hour/(60 × 60 seconds) = 37.5 μL/s
Therefore, a drug administered at a rate of 13.5 cL/hour has an administration rate of 37.5 μL/s.
Matthew has been collecting quarters in a jar. He has 176 quarters. What is the value of the coins in his jar?
Answer:
The correct answer is : 44 dollars.
Explanation:
A quarter is one fourth of a dollar that is the reason it is known as quarter. A quarter is 25 cents or 0.25 dollar in value. If Matthew has 176 quarters in his jar than the value of the total coins would be:
1 quarter = 0.25 dollar
1 quarter = 1/4 dollar.
4 quarter = 1 dollar
then, 176 / 4 = x dollar
= 44 dollar
Thus, The correct answer is : 44 dollars.
A tuna travels at a speed of 72 kilometers per hour. What is the speed of the tuna in meters per second?
Answer:
20 m/s
Explanation:
Name and describe the two types of observations. Please help!
Answer:
Quantitative and Qualitative :)
Explanation:
A. The pendulum would accelerate to the left
B. The pendulum would accelerate downward
C. The pendulum would accelerate to the right
D. The pendulum would accelerate upward
Answer:
The pendulum would accelerate to the left
Explanation:
hope this helps
Write an equation that shows the formation of a strontium ion from a neutral strontium atom
Answer:
See explanation
Explanation:
Sr(s) + 2HCl(aq) -----> SrCl2(aq) + H2(g)
Ionically;
Sr(s) + 2Cl^-(aq) ----> SrCl2(aq)
If we look at the reaction above, strontium atom was dissolved in hydrochloric acid. The strontium atom is now oxidized by the acid to give Sr^2+ ion according to the equation shown above.
A sample of liquid ammonia has a density of 0.7 g/mL. Find the mass of a 20 mL
sample of liquid ammonia. ***UNITS***
Answer:
Mass of liquid ammonia is 0.035g.
Explanation:
I hope this will help u
Have a nice day
A 4.80-gram piece of magnesium displaces 2.76 mL of water when it is placed in a graduated cylinder. What is the density of magnesium?
Answer:
1.73913043g/mL
Explanation:
Density is how much a substance would weigh per 1 mL of the substance. So it is measured by dividing weight (g) by volume (mL).
4.80g/2.76mL = 1.73913043g/mL
1. What are the characteristics of scientific thinking and investigating? 2.Why is science literacy important? 3.What skills and tools do scientists use? 4.Why is the use of the inquiry process (or scientific method) a practical way to approach science? 5.Why are scientific theories modified, but seldom discarded? 6.How has science and technology influenced everyday life?
I WILL GIVE BRAINLIEST TO ANYONE WHO ANSWERS!!!!!!!!
Answer: kindly check explanation
Explanation:
Characteristics of scientific thinking and investivating:
1) Empiricism : Also called empirical evidence maybe classed as natural evidences used to butress or support a certain notion or fact usually attainable from experience or teaching.
11.) Rational : Rational thinking or attribute could simply be tagged as reasonable and do not negate laid down facts.
111.) Skepticism: This is very imperative in scientific research as it opens the way to further research enabling researchers to gather more evidences required to establish a strong argument.
2.) IMPORTANCE OF SCIENCE LITERACY
Science literacy simply empowers mankind. Nourishing researchers or literates with the knowledge of its natural environment and enabling them understand, explore and exploit resources in our environment.
3.) Skills and tools scientist need :
Skills :
1) Curiosity: The ability to frame and and ask questions is key to establishing a purpose for research. Asking the right questions is key in a scientific process.
11) Data gathering or collection: Obtaining the right data capable of proferring the essential solution to our research question is key to obtaining logical insight.
111) Communication: Once research is complete, it is essential that researchers possess the skills required in transmitting their conclusion in a way which is both simple, logical and sensible.
Tools include common laboratory equipments such as beaker, testube, measuring cylinders, microscope and so on.
4.) The scientific or inquiry method provides a stepwise, easy to understand and logical approach to problem solving, Hence, providing a lucid and evidence - based conclusion which is both practicable and reproducible.
5.) The main reason for the modification of scientific theories is that they are susceptible to further research or study. As a result of evolution and change in trend depending on various natural and environmental factors, modification may occur in the form of review without abrogating previously existing studies.
6.) Science and technology has enabled mankind to adjust and cope with the continuous evolutionary changes in our environment. Enabling us to use these findings to ease our everyday living standard.
Physical science is the study of
A. How matter and energy interact
B. All answers are true
C.energy
D.matter
Answer:
b
Explanation:
Answer:
B
Explanation: All answers are true
Sulphur dioxide and oxygen reacts to form sulphur trioxide. The equilibrium mixture contain 5.0 × 10−2 M SO3, 3.0 × 10−3 M SO2 and 3.5 × 10−3 M O2. Calculate equilibrium constant for reaction?
Answer:
Keq = 79365
Explanation:
Based on the reaction of sulphur dioxide, SO2, with O2, to produce SO3:
2SO2 + O2 ⇄ 2SO3
The equilibrium constant of reaction (Defined as the ratio of concentrations of products over reactants powered to the coefficient of each reactant). For the reaction:
Keq = [SO3]² / [SO2]² [O2]
Replacing with concentrations of the problem:
Keq = [5.0x10⁻²]² / [3.0x10⁻³]² [3.5x10⁻³]
Keq = 79365