Answer:
1.9 miles per minute
Explanation:
The speed of a substance can be calculated by using the formula:
S = d/t
Where;
S = speed (m/s)
D = distance (m)
t = time (s)
In this question, the units for the distance and time are miles and minutes respectively. Hence, the speed is:
S = 85miles ÷ 45 mins
S = 1.888 miles/min
S = 1.9 miles per minute
please someone answer and help :)
The melting point of Paradichlorobenzene is 53.0C .In a laboratory activity two students try to verify this value .The first student records 51.5C,53.5C ,55.0C,52.3C and 54.2C.The second student records 52.3C,53.2C,54.0C AND 53.5C. A. Calculate the average value for the two students. B. Calculate the Percent error for each student. C. Which student is most precise ?Most accurate? Explain.
Answer:
a. 53.3°C.
b. Percent error for both students is 53.3°C
c. Both students are equal in accuracy.
2nd student is most precise
Explanation:
The percent error is defined as:
|M - T| / T * 100
Where M is measurement,
and T is theoretical value
a. To obtain the average of both measurements we need to sum the measurements and divide these in the number of measurements:
51.5°C+53.5°C+55.0°C+52.3°C+54.2°C+52.3°C+53.2°C+54.0°C+53.5°C / 9
= 53.3°C
b. Percent error for 1st student:
51.5°C+53.5°C+55.0°C+52.3°C+54.2°C / 5 = 53.3°C
|53.3°C - 53.0°C| / 53°C * 100
0.57%
Percent error for 2nd student:
52.3°C+53.2°C+54.0°C+53.5°C / 4 = 53.3°C
|53.3°C - 53.0°C| / 53°C * 100
0.57%
c. Now, precision is how close are the measurements to each other and the accuracy how close are the measurements to the theoretical value:
The accuracy is obtained with percent error, the lower percent error the most accurate measurement. That means:
both students are equal in accuracy.
And precision is obtained with relative standard desviation.
Desviation standard / Average * 100
(We can solve the standard desviation in a scientific calculator):
1st student:
2.65%
2nd student:
1.34%
The lower RSD the most precise measurements.
2nd student is most preciseWhich type of bond is salt? a. covalent b. valence c. metallic d. ionic
Answer:
D. Ionic
Explanation:
It has ionic bonding! Good luck ^^
In photosynthesis, what are the polar molecules?
Answer:
in photosynthesis polar molecules are molecules that have a diffrent arangment in molecules for example polar water molecule is when oxegen is on one end and the hydrogen is on the other. olmost any compound can have a polar or non polar molecule.
Explanation:
3. How are the protons held in the
nucleus?
O opposite charges
O strong nuclear force from neutrons
Owhich nuclear wall
Could cellular respiration
happen without photosynthesis? Explain your
reasoning
Answer:
No
Explanation:
Without photosynthesis, there would be no sugar, without which there could be no cellular respiration.Both animal cells and plant cells depend on cellular respiration for their energy needs, because both animal cells and plant cells need ATP.
Question 2: Which of the following is NOT true about streams?
A. A large stream is called a river
B. All streams flow into the ocean
C. Tributaries are smaller streams
D. All streams flow downslope
Question 3: Which of the following statements is NOT part of the water cycle?
A. Water falls precipitation back to earth
B. Water soaks into the ground
C. Water evaporates from bodies to water on earth
D. Water dissolves minerals from rocks it flows over
Question 4: Which statement best describes a stream with a steep gradient?
A. It flows slowly,producing a wide valley
B. It flows slowly producing a V-shaped valley
C. It flows rapidly producing a V-Shaped valley
D. it flows rapidly producing a wide valley
Answer:
q 3 c q 2 d
Explanation:
which formula is an empirical formula?
The reaction for the combustion of acetylene is shown. Explain why this reaction is a redox reaction by identifying the oxidation numbers that change, what is oxidized, what is reduced, and what happens to the electrons during the reaction. 2C2H2 + 5O2 → 4CO2 + 2H2O
Answer:
2 C2H2 (g) + 5 O2 (g) → 4 CO2 (g) + 2 H2O (l)
Explanation:
Redox reaction: In this type of reaction, oxidation and reduction reaction occurs simultaneously in same chemical reaction.
2C_2H_2+5O_2\rightarrow 4CO_2 + 2H_2O2C
2
H
2
+5O
2
→4CO
2
+2H
2
O
This reaction is a redox reaction :
Removal of hydrogen or addition of oxygen is termed as oxidation. in above reaction, removal hydrogen from acetylene gives carbon-dioxide.
Removal of oxygen or addition of hydrogen is termed as reduction. in above reaction, removal of one oxygen atom from oxygen molecule with addition of two hydrogen atoms gives water
The oxidation number of carbon in acetylene is -2.
The oxidation number of carbon in carbon-dioxide= +4
Oxidation number of carbon increases after the reaction which means that carbon is getting oxidized.
The oxidation number of oxygen in oxygen gas = 0
The oxidation number of oxygen in water = -2
Oxidation number of oxygen decreases after the reaction which means that oxygen is getting reduced.
The electrons released during oxidation are transferred to the species which are undergoing reduction reaction.
Answer:
Just put this, or something like it:
The oxidation number of carbon changes from -1 to +4.
The oxidation number of oxygen changes from 0 to -2.
Carbon is oxidized.
Oxygen is reduced.
Electrons are transferred from carbon to oxygen.
Explanation:
scientists studying squirrels in a forest observed that the squirrel population decrease over a period of five years. which statement is the most likely explanation for the decrease in the population?
Answer:
1.An increment of predators
2.unavailability of food resources due to change in climate causing famine
3.Spread of diseases over time that might kill the squirrels
4.An increment of squirrels which caused high competition on food,thus some of them had to migrate
5.Might be fire break out over some time that caused death to some squirrels in the reasoning of the period of time
8.
Blank is the transfer of energy by electromagnetic waves.
Your answer
Balance the following chemical equations
Explanation:
2Na + I₂ → 2NaI 2KClO₃ → 2KCl + 3O₂K₃PO₄ + 3HCl → 3KCl + H₃PO₄As a result of the Law of Conservation of Mass, during a chemical change the mass of the
products are equal to the mass of the:
A. particles
B. elements
C. reactants
D. compounds
Answer:
D. Reactants.
Explanation:
The law of conservation of mass states that mass in an isolated system is neither created nor destroyed by chemical reactions or physical transformations. According to the law of conservation of mass, the mass of the products in a chemical reaction must equal the mass of the reactants.
I have the coldest temperature of the atmosphere. Who am I?
Answer:
Jack Frost of course!!!!!!!
HURRY ITS IS DUE SOON
Answer:
use the meaning of the word see what is similar and what is different about them
How many number of oxygen molecules are required to produce 0.22 g of CO2 according to the reaction?
c+o2=co2
PLS ANSWER FAST!!! HURRY I NEED THIS ASAP!!
Which statement about chemical reaction rates is true?
The reaction rates cannot change.
The reaction rates can increase.
The reaction rates are always constant.
The reaction rates cannot decrease
Answer:
The reaction rates cannot charge
Explanation:
Answer:
The answer is B
Explanation:
why do the Noble gases have the highest ionization energies across a period?
Answer:
ionization energy decreases from top to bottom in groups, and increases from left to right across a period. So technically, the noble games have the largest ionization energy.
Explanation:
The density of water is 1.00 g/mL. Which substance below can float on water?
Answer:
ice, air, ducks and fabric
Explanation:
its common sense
The tendency of an atom to attract electrons to itself is ionization energy. effective nuclear charge. electron affinity. electronegativity.
Answer:
electronegativity
Explanation:
Answer:
THe tendoncy is electronegstivity
Explanation:
Im a big brain person
6. Which of the following element pairs would most likely form an ionic compound? (5pts)
a. Ca and Ni b. Cu and Ar c. F and S d. Zn and K e. Na and Cl f. V and O g. He and Xe h. Sn and Na i. C and Br j. Sr and P k. Cr and I l. Ag and NO 3
Answer:
b
Explanation:
State Henry's law. Give an example of Henry's law.
Answer:
Found this off of google, "Henry's law comes into play every time a bottle of Pepsi (or any other carbonated drink) is opened. The gas above the unopened carbonated drink is usually pure carbon dioxide, kept at a pressure which is slightly above the standard atmospheric pressure."
An electron moves from an excited state back to the ground state releasing
4.56 x 10-19 J of energy. a) Find the frequency of the photon of light that would be released. b) Find the
wavelength in nm.
Explanation:
The first step in this problem is to convert the wavelength, λ, to a frequency, ν, and
then calculate the energy of the photon using ε = hν. In such problems you must take
care to use a consistent set of units. We will use S.I. units. Thus,
λ = 18900 Å = 18900 x 10–10 m = 1.89 x 10–6 m
The frequency associated with this wavelength is given by:
ν = c/λ = (3.00 x 108 m s–1 ) / (1.89 x 10–6 m) = 1.59 x 1014 s–1
The energy ε associated with a photon of this frequency is:
ε = h ν = (6.626 x 10–34 J s) (1.59 x 1014 s–1) = 1.05 x 10–19 J
Note -- the ENERGY of this photon corresponds to a DIFFERENCE between
energy levels of the H atom
The energy levels for the H atom are given by:
εn = (–21.8 x 10–19 J) / n2 ; where n = 1,2,3,4,.............
Thus, ε1 = –21.8 x 10–19 J; ε2 = –5.45 x 10–19 J
ε3 = –2.42 x 10–19 J; ε4 = –1.36 x 10–19 J
We now seek an ENERGY LEVEL DIFFERENCE which matches the energy of the
photon.
We see that the electronic transition which gives rise to an EMITTED photon with
energy ε = 1.05 x 10–19 J is:
ninitial = 4 → nfinal = 3
2. A series of spectral lines in emission is characterized by a common value of nfinal -- i.e.
the quantum number of the level at which the transition terminates. Since the 18900 Å
line arises from a transition in which ninitial = 4 and nfinal = 3, the series to which it
belongs is characterized by nfinal = 3. The series limit for this series of emission lines is
the wavelength that would correspond to the transition ninitial = ∞ to nfinal = 3
From the energy level expression given in problem1 we see that:
ε∞ = (–21.8 x 10–19 J) (1/ ∞2) = 0
What is the specific heat of a substance that absorbs 1000 joules of heat when a sample of 25 g of the substance increases in temperature from 10.0C to 60.0C
Answer:
1250000
Explanation:
Specific heat is mass times specific heat capacity times change in temperature to get chance in temperature minus the old temperature from the new temperature then complete equation hence 25g×1000j×(60-10)
25g×1000j×50
=1250000g/j/degree Celsius
Help! I am in a hurry! Will get brainliest if correct!
Answer:
nonmetel
Explanation:
Answer:
Its a non-metal
Explanation:
Elements that tend to gain electrons to form anions during chemical reactions are called non-metals. These are electronegative elements. They are non-lustrous, brittle and poor conductors of heat and electricity (except graphite). Non-metals can be gaseous, liquids or solids.
Which of the following happens to the particles when the temperature of liquid water drops?
kinetic energy decreases
kinetic energy increases and then decreases
kinetic energy increases
kinetic energy stays constant
Answer:
The Kinetic energy decreases
Explanation:
because the speed of the molecules slows down.
what information can you figure out about an atom using only the atomic number?
PLS HELP ME PLS I'LL GIVE BRAINLIEST TO WHOEVER ANSWERS FIRST OR HAS THE BEST ANSWER
Which of the following is a hypothesis for an experiment measuring solubility of sodium sulfate?
A. O Sodium sulfate will dissolve better in cold water
B.
Sodium sulfate is toxic (poisonous; deadly) to humans.
c. Add sodium sulfate to water
D. O Sodium sulfate is a white powder
What is true about atoms when they bond? There may be more than one answer.
1. Bonded atoms can never be taken apart
2. Electrons can be transferred
3. They form compounds
4. Compounds have the same characteristics are the atoms that make it up
5. Electrons can be shared
Answer:
3. 5. and i think thats it
Answer:
3. 5. and i know it is right
Explanation:
