Answer:
11. A
12. B
13. D
14. E
15. C
1. . Are these physical or chemical changes? a) slicing cheese
b) acid reacting with baking soda to make carbon dioxide
c) emptying a gas cylinder of air
d) cooking eggs
Answer:
physical change
slicing cheese
acid with baking soda
.......cookoing eggs
A hose delivers water to a swimming pool that measures 9.0 m long by 3.5 m wide by 1.75 m deep. It requires 97 h to fill the pool. At what rate in liters per minute will the hose fill the pool?
Answer:2
Explanation:
7. What is ultraviolet radiation?
Answer:
Ultraviolet radiation is a form of electromagnetic radiation that comes from the sun.
Classify these compounds as acid, base, salt, or other. Drag the appropriate items to their respective bins.
HCOOH, CH3OH, NaOH, HNO3, NaBr, NH3, CO2, KCl
HCOOH is an acid, KCL is a Salt, NaOH is a base.
Acids Bases and SaltsAn acid is defined as a substance which when dissolved in water produces hydronium ion (H3O+), neutralizes bases, tastes sour and turns blue litmus red.
Acids incldes:
HCOOH-weak acidHNO3-Strong acidA Base is a substance which in its aqueous solution produces hydroxyl ions (OH–), neutralizes acids , tastes bitter and turns red litmus blue
Bases incldes:
NaOHNH3A Salt is an ionic compound produced from the neutralization reaction of acids and bases. it is neutral substance and has no effect on litmus.
NaBrKCLThe folloing can be classifed as other or in aqueous solution as :
CO2-acidic oxide, Bronsted lewis acid CH3OH -Bronsted-Lowry acidLearn more on acids base and salts here:https://brainly.com/question/2927542
Why is it important to use chemicals of high quality (purity) and exact(correct) concentrations in experiments?
Answer:
To produce good or targeted result
It is important to use chemicals of high quality and correct concentrations in experiment so that we can obtain the predictable result in an experiment
Purity of substances/chemicals is very important when performing experiments in the laboratories, because it plays an important role in the determination of the chemical properties of substances which will have a direct effect on the result obtained from the experiment. likewise using the correct concentration of reagents
During experiments to obtain the best/predictable result in an experiment it is of best practice to make use of chemicals of high quality and also at the exact(needed) concentrations, that way the predictable result of the experiment will be obtained.
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20,000 $ give a way but answer this first
Plz
12.Write the basis of naming of the following elements. 1.Neptunium,2.Mendelevium,
Answer:juhygjdkeExplanation:
Mendelevium is named for Dmitri Mendeleev who produced one of the first periodic tables.
Abelson first found neptunium in 1940 after uranium had been bombarded by neutrons from the cyclotron at Berkeley, California. ... The element was named after the planet Neptune, which is the first planet beyond Uranus.
Answer in explanation
Explanation:
neptunium was named after the discovery of the planet neptune in september 23 1846
mendelevium was named as dimitri mendeleev
Please help me please find the answer
Please do this
Please do this
Plzz
Total distance=60m+40m=100m
Total Time=6+4=10s
#a
[tex]\boxed{\sf Speed=\dfrac{Distance}{Time}}[/tex]
[tex]\\ \sf\longmapsto Speed=\dfrac{100}{10}[/tex]
[tex]\\ \sf\longmapsto 10m/s[/tex]
#b
Displacement=AC=60m
[tex]\\ \sf\longmapsto Velocity=\dfrac{Displacement}{Time}[/tex]
[tex]\\ \sf\longmapsto Velocity=\dfrac{60}{10}[/tex]
[tex]\\ \sf\longmapsto 6m/s[/tex]
#C
Distance=60mtime=5s[tex]\\ \sf\longmapsto Velocity=\dfrac{60}{5}=12m/s[/tex]
#d
The velocity of A to C is greater than Velocity from C to A
what is the oxidation number of chloride ion HClO ?
The oxidation state of Cl is +1
We are driving to Orlando. The sign says
that it is 145 kilometers to Orlando.
How many meters is it to Orlando?
A: 0.145
B: 145,000
C: 14.5
D: 14,500
Answer:
b
Explanation:
there is 1000m in 1 km so the ans is literally just 145x1000 m which is 145000m
Answer:
B! 145,000
Explanation:
your welcome love!
A student performs an experiment to determine the molar mass of magnesium oxide. The student repeats the experiment five times and collects the following data: 40.220gmol, 40.654gmol, 40.314gmol, 40.165gmol, and 40.554gmol. What is the relative standard deviation (RSD) for this set of data?
The relative standard deviation for the set of data obtained by the student is 0.470%
The formula for calculating the relative standard deviation is given below as:
Relative standard deviation (RSD) = (S * 100)/x
where S stands for the standard deviation and x is the mean of the data set.
The following are the steps to calculate to determine the relative standard deviation using the given formula:
Step 1: Calculate the mean of the numbers in the data set.
mean, x = sum of numbers / number of numbers
(40.220 + 40.654 + 40.314 + 40.165 + 40.554)/5
mean = 40.381 g/mol
Step 2: Subtract the mean from each number in the data to determine the deviation for each number and then square the deviations.
(40.220 - 40.381)² = 0.0259
(40.654 - 40.381)² = 0.0745
(40.314 - 40.381)² = 0.00449
(40.165 - 40.381)² = 0.0466
(40.554 -40.381)² = 0.0299
Step 3: Sum the squared deviations.
0.0259 + 0.0745 + 0.00449 + 0.0466 + 0.0299 = 0.181
Step 4: Determine the variance by dividing the sum of the squared deviations by the total number of values.
Variance = 0.181/5 = 0.0362
Step 6: Determine the standard deviation of the data by taking square root of the variance.
Standard deviation, S = √0.0362 = 0.190
Step 7: Determine the relative standard deviation by inserting the values in the formula, (RSD) = (S * 100)/x
RSD = (0.190 * 100)/40.381
RSD = 0.470%
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Anti coagulant usend in blood sampling
Answer:
Ethylenediaminetetraacetic acid (EDTA), heparin, and citrate are the most commonly used anticoagulants (39–41). pls mark me branilest
What is the Molality of a solution prepared by dissolving 84.7 g of KMnO4 (potassium permanganate, an oxidizing agent) in 165 g of water?
a) 0.513 m
b) 11.3 m
c) 0.308 m
d) 3.25 m
e) 0.958 m
An unknown compound has the following chemical formula: where stands for a whole number. Measurements also show that a certain sample of the unknown compound contains of magnesium and of chlorine. Write the complete chemical formula for the unknown compound.
Answer: This is only a guess: The "following chemical formula: " doesn't appear on my screen. But since you mentioned Mg and Cl, I would guess MgCl2
Explanation: Mr loses 2 electrons while each Cl gains one each: Two chlorines for every 1 magnesium.
In the laboratory, open-toed shoes and shorts:
a. Are potentially dangerous and should not be worn.
b. Are OK if the weather is hot.
c. Are all right if you are wearing a lab coat
d. Are OK if they are in style.
Answer:
a. Are potentially dangerous and should not be worn.
Give reasons ,Argon is an inert gas.
Answer:
The outermost (valence) shell of argon has eight electrons, making it exceedingly stable and, thus, chemically inert. Argon atoms do not combine with one another; nor have they been observed to combine chemically with atoms of any other element.So argon is an inert gas
Answer:
because argon have 8 electrons in there outmost shell
which is enough to make it stable
Which term best describes the important pieces of information that scientists gather and record during an experiment?
conclusions
data
research
supplies
Answer:
conclusions i think i am not confirmed
Answer:
b-data
Explanation:
right on the unit test review on edge
brainliest???
Use the blue slider labeled mass to carefully adjust the mass of the red block until neither sinks nor floats. The block should stay wherever your cursor places it without moving up or down. Next remove the block from the water and put it in the scale. Record its new mass.
Answer:
4.1 grams
Explanation:
Answer:
4.1
I solve this solution and then i got correct on it so its 4.1 thank you!
An irregular object with a mass of 18 kg displaces 2.5 L of water when placed in a large overflow container. Calculate the density of the object. (answer = 7.2 kg/L or 7.2 g/mL or 7.2 g/cm3)
Answer:
7.2 kg/L
Explanation:
Density = mass ÷ volume
18 kg ÷ 2.5 L = 7.2 kg/L
The units didn't change in this scenario.
Please help ASAP!!!!!!!!
Answer:
the correct answer is option B batteries use chemicals to store energy
We have that the statement that remains true about batteries is
"Batteries use chemical to store energy "
Option B
-All battery are able to be recharged that is not correct as some batteries are non rechargeable
-A battery is a device composed of petrochemical cells, that rel sole upon the energy from chemical reactions to give off charge
-A battery is a device that is use to store energy. Therefore Batteries to not conserve energy
Hence the statement that remains true about batteries is
"Batteries use chemical to store energy "
Option B
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The neutrons within the nucleus of an atom have what charge?
A)negative.
B)same as an electron.
C)same as a proton.
D)no charge.
Answer:
the answer is D.
Explanation:
your welcome :)
Answer: D). No Charge
Explanation: The neutrons within the nucleus of an atom have no charge.
How does a hypothesis differ from a scientific theory? (1 point)
O Hypotheses can change with new evidence, but theories remain constant.
O Theories always lead to the development of new scientific ideas.
o Hypotheses are testable, while theories only exist conditionally.
o Theories are well established with lots of evidence to support their claims.
Answer:
the answer is actually D. (theories are well established with lots of evidence to support their claims)
Explanation:
i just took the quiz
A hypothesis is a presented reason for a phenomenon based on limited proof and evidence. A scientific theory is an elucidation of an element that has been constantly experimented with and confirmed per scientific approach.
Theories are well established with lots of proof to back their assertions.
What is the difference between the theory and hypothesis?Scientific theories are established based on the evidence and repetitive experimental procedures to prove and establish them correctly.Theories can change over time as new supporting evidence are found or new procedures are established to amend the old theory.A scientific theory recapitulates a hypothesis that has been reinforced with repeated experiments and observations.A hypothesis should be an instinctive justification or the potential correlation that lies between several phenomena and depends on the scientific theory.Therefore, option D is correct.
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Which one of the following is NOT the unit of wave number:
m-1
cm-1
mm-1
cm
Answer:
e
Explanation:
cm is not the unit of wave number out of the following.
What is a wave number?Definition: Total number of wave cycles present in a unit distance is termed a wave number.
Wave number is always a reciprocal of the unit of distance.Wave number is denoted by the letter 'k'.The formula for wave number is 2π/λ where λ is the wavelength. Since wave number is always reciprocal, cm is not the unit for a wave number. The higher the wave number, the higher the frequency and energy.To learn more about wave number, refer to:
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why is mitochondria called the power house of a cell ?
Answer:
Hey mate....
Explanation:
This is ur answer....
Mitochondria are tiny organelles inside cells that are involved in releasing energy from food. This process is known as cellular respiration. It is for this reason that mitochondria are often referred to as the powerhouses of the cell.
Hope it helps!
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A cylinder fitted with a movable piston and filled with a gas has a volume of 188.5mL at 26.7 °C when the applied pressure is 755.2 torr. The temperature of the oil bath surrounding the cylinder was increased to 165.2 °C, and the load on the piston was changed. Careful measurement now gave a value of 210.5mL for the volume. What was the final pressure in the system, in torr? Select one:
O a. 715.5 tor O b. 576.9 torr Oc. 988 6 torr O d. 1233 torr 462.6 tor
Answer:
C
Explanation:
To find the new pressure, we will use this formula: P₁V₁/T₁ = P₂V₂/T₂
P₁ = Original pressure (755.2)
V₁ = Original volume (188.5)
T₁ = Original temperature in kelvins (26.7 + 273.15 = 299.85)
P₂ = Final Volume (?)
V₂ = Final volume (210.5)
T₂ = Final temperature in kelvins (165.2 + 273.15 = 438.35)
Here is our equation
(755.2)(188.5)/(299.85) = (210.5)P₂/(438.35)
Hopefully, you have a calculator handy because this equation will end up looking like this:
474.75471 = (0.48021)P₂
Divide both sides by the coefficient
474.75471/0.48021 = (0.48021)P₂/0.48021
P₂ = 988.64
13. Find the total number of atoms present in the following molecules. a. 5 H₂O b. Zn Cl₂
Answer:
A= 15 atoms B= 3
Explanation:
5 x 2 + 5 x 1
3 + 2 x 1
3.
Carlos is trying to figure out the best place to put his router in order to get the best
signal. Which is not an independent variable?
A. Distance from the router
B. Signal strength at the computer
OUTPU
C. The number of walls between the router and computer
STATIO
D. The number of devices on the router
Answer:
right answer is option no c
An atom has 15 protons and 14 Neutrons. What is the atomic number of this atom?
Answer:
Silicon
Explanation:
Therefore the isotope with 14 protons and 15 neutrons is Silicon-29.
An atom has 15 protons and 14 Neutrons. The atomic number of this atom is 14 and the element is silicon.
What is the atomic number?The atomic number of an element is its total number of protons or the total number of electrons. The atomic number is written down the element. It can be calculated by knowing the numbers of protons and electrons.
The element here is silicon, whose number of protons, electrons, and neutrons are equal, which is 14. These are the charged particles that are present in the atoms of the element.
The number of band protons is equal to an element. The atomic number will be its number of protons. The isotope with 14 protons and 15 neutrons is Silicon-29.
Thus, the atomic number of the element is 14 if it has 15 protons and 14 Neutrons. The element is silicon.
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2. State a common metric unit and symbol obtained from each of the following instruments.
(a) metric ruler
(b) balance
(c) graduated cylinder
(d) thermometer
Answer:
cm
Explanation:
for short measurements
Homework 2
1. A scientist is attempting to check the relative atomic masses on the periodic table. He works
with three different compounds that contain only C and another compound. These are
diatomic compounds with a formula of CX. He finds the following information. If he
assumes the weight of C is 12 what is the weight of the other element and its identity.
Wt C
Wt X
Compound 1
4.2
4.9
Compound 2 3.5
4.67
Compound 3 1.3
3.47
the concepts of mole and chemical reactions, the element of the three compounds can be found.
compound 1 carbon - Nitrogen CN
compound 2 carbon - Oxygen CO
compound 3 carbon - Sulfur CS
Chemical reactions are expressed in moles of each constituent element. The mole is one of the fundamental quantities of physics and is defined as the amount of matter in 0. 012 kg of carbon 12, in practical form the moles of a given element in a chemical reaction is found with the expression
n = m / Pm
where n is the number of moles, m the mass of the element and PM the molecular weight (taken from the periodic table) of the element.
Let's apply to our compounds as the chemical formula is CX, there is an atom of each element, let's look for the moles of carbon.
compound 1
mass of coal 4.2
carbon mole
n_C = 4.2 / 12
n_C = 0.35 mol
as in the chemical reaction there is an atom of each element, there are also 0.35 moles of the unknown element, let's find its molecular weight (PM)
PM = m / n
PM = 4.9 / 0.35
PM = 14 gr / mol
When reviewing the periodic table this weight corresponds to Nitrogen(N)
The elect is Nitrogen
compound 2
carbon mass 3.5
carbon moles
n_C = 3.5 / 12
n_C = 0.29167
moles of unknown element n = 0.29167
mass of unknown element m = 4.67
molecular weight
PM = 4.67 / 0.29167
PM = 16 gr / mol
Checking the periodic table corresponds to the element Oxygen (O)
Compound 3
carbon mass 1.3
carbon moles
n_C = 1.3 / 12
n_C = 0.1083
moles unknown element n = 0.10833
mass unknown element m = 3.47
PM = 3.47 / 0.10833
PM = 32 gr / mol
In the periodic table the element Sulfur (S) has this molecular weight
Using the concepts of mole and chemical reactions, the elements of the three compounds can be found.
compound 1 carbon - Nitrogen CN
compound 2 carbon - Oxygen CO
compound 3 carbon - Sulfur CS
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what is a characteristic of matter that allows it to change to something new? THE CORRECT ANSWER GETS BRAINLIEST!!!!
Answer:
a chemical property
Explanation:
