Answer:
Explanation:
1. New substances such as carbondioxide and water is formed.
2. There is evolution of gas bubbles. Gases are released.
3. There is either the absorption of energy or release of energy in form of light and energy.
4. The reaction is irreversible i.e it cannot be reversed, it is permanent once the reaction take place.
5. There is a change in both odor and smell.
A chemical change is a change where new substances are formed due to changes in the properties.
4. The radius of a hydrogen atom is 37 pm (1pm 10"m). How many hydrogen atoms lined up side to side would it take to make 1.00 inch? (Hint start with 1.00 inch)
Answer:
V = 4/3 * 3.1416 * (37x10-10)3
V = 2.12x10-25 cm3
d = m/V
d = 1.67x10-24 / 2.12x10-25 = 7.87 g/cm3
The difference in temperature, let's convert F to ºC:
ºC = -80-32/1.8 = -62.22 ºC
dT = -92.6 + 62.2 = -30.4 ºC
The number of hydrogen atoms lined up side to side to make 1.00 inch is equal to 3.43 × 10⁷ atoms when the radius of one H-atom is 37 pm.
What is the radius of a hydrogen atom?The atomic radius of a hydrogen atom is the distance between the center of the nucleus to the boundary of the electron that surrounds it.
Given, the radius of the hydrogen atom = 37pm
Then the diameter of the hydrogen atom = 37 + 37 = 74 pm
We know that 1 pm = 10⁻¹¹ m
Then the diameter of the one H - atom = 74 × 10⁻¹¹ m
The value of 1 m = 100 cm then the diameter of H-atom = 74 × 10⁻⁹ cm
As we know, the value of one inch = 2.52 cm
So, if 74 × 10⁻⁹ cm length takes H-atom = 1
Then, 2.52 cm would take hydrogen atoms = 2.52/ 74 × 10⁻⁹ = 3.43 × 10⁷
Therefore, 3.43 × 10⁷ hydrogen atoms lined up side to side to make 1.00 inch.
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___________ is used to produce 30% of the world's electricity.
Answer:
oil
Explanation:
coal be making most of the electricity
Answer:
power
Explanation:
write an Argument for people of westfield identifying the reddish brown substance. Plz answer this is due tomorrow!!
Answer:
The reddish-brown substance is a different color than the fertilizer, which is white, and the substance that makes up the pipe, which is gray. This means that they cannot be the same substance because they do not have the same properties. The atomic models show that the reddish-brown substance is made up of different repeating groups of atoms than the fertilizer and the pipe substance. The difference in atoms caused the difference in properties.
Explanation:
lul
People of westfield identifying the reddish brown substance and that substance is rust i.e. iron oxide.
What is rust?Rust is a chemical compound which is formed by the oxidation reaction between iron and oxygen for the formation of iron oxide.
People of westfield observed the reddish brown color in the water, that is the rust compound which is obtained by the chemical reaction occur between the iron pipes and the compound present in the fertilizers that are present in water.
Hence, the reddish brown substance in rust.
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How many molecules are there in 3.20 grams of NH4SO2
Answer:
0.0389757845886336
Explanation:
What happens to the number of valence electrons as you move from element 1 to element 18 on the periodic table?
A)the number of valence electrons decreases
B)the number of valence electrons decreases then increases in a predictable sequence
C)the number of valence electrons increases
D)the number of valence electrons increases then decreases in a predictable sequence
Answer:
C
Explanation:
Answer: The answer is C
Explanation:
Which is the correct formula for the ionic compound that results from these two atoms? PLS HELP!!!
Answer:
If I am not wrong is C x2y5
Explanation:
The concept of valency is used here to determine the formula of the ionic compounds. The number of valence electrons in 'X' is 2 and that of 'Y' is 5. The formula is X₃Y₂. The correct option is D.
What is an ionic compound?The crystalline solids which are formed by neatly packed ions of opposite charges are defined as the ionic compounds. These compounds are formed by the combination of metals with non-metals.
The combining capacity of an element is given by valency. The elements belonging to the same group have the same valency. It is related to how many electrons are in the outer shell.
Here the number of valence electrons in 'X' = 2
The number of valence electrons in 'Y' = 5
The element 'X' need 6 electrons to attain the octet and 'Y' needs 3 electrons to attain the octet.
X - 6
Y - 3
The formula of the ionic compound is X₃Y₂.
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How does heat transfer through conduction?
from the warm object to the cool object
D) from the cool object to the warm object
from the warm object into the air
from the air to the cool object
Answer:
from the warm object to the cool object
Explanation:
Think of heat as a straight line, and the warmer the object the higher its gradient. Now, if you have cold object is lower in heat energy, the heat energy from the warm object will go down the gradient to the cool object. Note, in conduction, there must a contact between the two objects.
What are high tides caused by
Answer: the moons gravitational force
Explanation:
When 5,946 J of heat is added to 79.75 grams of oil at 37˚C , the temperature increases to 64˚C. What is the specific heat of the oil?
Answer:cool kid
Explanation:cool kid
PLEASE HELP ILL DO WHATEVER Bryan is doing a triathlon and you need to calculate his average speed for all three events. He swims 1km in 0.4 hrs. He rides his bike 50km in 1.5hrs and he runs 10km in 0.7 hrs.
Answer:
toda
Explanation:
:todo lo que tienes que hacer es hacer la cosa
Answer:
16.6km/h
Explanation:
Speed is distance/time.
speed for 1st event = 1/0.4 = 2.5km/h
speed for 2nd event = 50/1.5 = 33.3 km/h
speed for 3rd event = 10/0.7 = 14.28 km/h
Average speed = 2.5 + 33.3 + 14.28 /3 = 50/3 = 16.6 km/h
0.14g of methanol is burnt and 3.04kJ of heat is released. Calculate the enthalpy of combustion of methanol.
Answer:
-694.8 kJ/mol ≅ -695 kJ
Explanation:
The enthalpy of combustion (ΔHc) is defined as the amount of heat that is released when 1 mol of the compound is burned. We have the mass of methanol (0.14 g) and we have to calculate the moles present in that mass. For that, we need the molecular weight of methanol, which is calculated from the molar mass of the chemical elements.
Methanol: CH₃OH
Mw(CH₃OH) = (12 g/mol x 1 C) + (1 g/mol x 3 H) + 16 g/mol O + 1 g/mol H = 32 g/mol
moles of CH₃OH = mass/Mw(CH₃OH) = 0.14 g/(32 g/mol) = 4.4 x 10⁻³ mol
As the heat is released, the change in enthalpy is a negative value: -3.04 kJ.
Finally, we divide the released heat (-3.04 kJ) into the number of moles of CH₃OH:
ΔHc= (-3.04 kJ)/(4.4 x 10⁻³ mol CH₃OH) = -694.8 kJ/mol ≅ -695 kJ
Las reacciones de adición son... 2 reactivos producen 2 productos nuevos 2 reactivos producen un solo producto 1 reactivos produce 2 productos El reactivo es una sustancia carbonada y O2
Answer:
Las reacciones de adición son... 2 reactivos producen un solo producto.
Explanation:
Las reacciones de síntesis o combinación ocurren cuando dos o más reactivos forman un solo producto; generalmente se libera calor, siendo reacción exotérmica. También se les conoce como reacciones de adición.
En otras palabras, las reacciones de adición son aquellas en las cuales todos los átomos de los reactivos van a formar parte de un único producto. Uno de los reactivos (al que se le suele llamar sustrato) debe contener un enlace doble, o uno triple. Las Reacciones de Adición se dan principalmente en Química Orgánica donde los dobles y triples enlaces son comunes.
La característica principal de estas reacciones es que durante el proceso, el doble o triple enlace se rompe formando nuevos enlaces.
Las reacciones de adición son... 2 reactivos producen un solo producto.
i'll give brainliest
You live near the ocean and your friend lives further inland. Based on this, what can you say is most likely different about the climate in your area from your friend's area in the winter?
Your friend has colder winters than you do.
Your friend has warmer winters than you do.
You have less precipitation than your friend does.
You get more sunshine in the winter.
Answer:
I'm thinking its "Your friend had colder winters than you do."
Explanation:
It is not "Your friend has warmer winters than you do." Or "You Have less precipitation than your friend does." I was doing this quiz before that had this question and its not those.
In the ocean side the the winter will be colder by the ocean breeze in the day time. The location of your friend farther from the ocean will have warmer winters than you.
What is sea breeze ?Any wind that flows from a big body of water onto or onto a landmass is called a sea breeze or an onshore breeze. Sea breezes form as a result of changes in air pressure brought on by the different heat capacities of water and dry land. Sea breezes are therefore more confined than prevailing winds.
A sea breeze is frequently seen along coasts after sunrise because land warms up far more quickly than water does when exposed to solar radiation. While dry ground also cools faster than water, a land breeze or offshore breeze has the opposite effect.
In winter seasons, along with the sea breeze make the climate more colder than that in locations farther from oceans. Hence, option b is correct.
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Which statement is true about heat transfer? *
5 points
a. Heat can only transfer when touching another object.
b. Heat always travels up.
c. Heat transfers from cooler to warmer objects.
d. Heat transfers from hotter to cooler objects.
Answer: A
Explanation:
heat always passes from a warmer object to a cooler object until all objects are the same temperature. Conduction is how heat travels between objects that are touching. Conduction travels fastest through solids, but liquids and gases can also conduct heat.
PLEASE ANSWER ALL I WILL GIVE BRAINLIEST PLEASE!!
Light
6CO2 + 6H20
CGH12O6 +602
Chlorophyll
The equation above describes the chemical reaction that occurs during
photosynthesis. What happens to the light energy that is shown in the reaction?
Answer:
Light energy acts as a catalyst that speeds up the rate of photosynthesis
Explanation:
How much energy does a wave with a frequency of 7.0 x 1012 Hz have
Answer:
4.64 × 10⁻²¹ J/s
Explanation:
[Only if the wave travels at the speed of light]
Because a wave presumed to be at light speed is a photon, E = hf.
If frequency is not given, E = hc/λ
c is the speed of light in meters per second. c = 299, 792, 458 m/s.
λ is the wavelength which is dependent.
h or plancks constant = 6.62607004 × 10⁻³² m² kg / s.
E is in units of J / s or jules ( m² kg ) per second.
If the wave has a frequency of 7.0 x 10¹² Hz or 7 THz (Tera-Hertz).
E = (6.62607004 × 10⁻³⁴) × (7.0 × 10¹²) =
46.38249028 × 10⁻²² =
4.638249028 × 10⁻²¹ J/s ≈
4.64 × 10⁻²¹ J/s
Which of the following best explains why bonds form between atoms?
A. Because the energy is at the minimum.
B. Because of the attractive forces between the nucleus of one atom and the electrons of the
atom.
other
C. Because atoms like to share electrons, which results in a stable system.
D. Because forming a bond fills up the valence shell of the atom giving a full octet.
19 Does ona moleculo of u
Answer:
D
Explanation:
I believe the answer is D because atoms are always seeking to fill up their outer electron shell/valence shell and want to gain a full octet.
Passenger airplanes take off in the troposphere but can eventually move into
the stratosphere. The planes may remain in the stratosphere until it is time to
land. Why do you think planes fly in the stratosphere?
As you walk up a mountain air pressure?
1. increases
2. decreases
3. remains the same
Answer:
decreases
Explanation:
Answer:
Decreases
Explanation:
There is less gas molecules and the air gets thinner the higher up you go
HELP ME WILL MARK BRAINIEST
The metal lid is stuck on a glass jar of jelly. Why does running hot water over the lid help you get the lid off? *
a. Thermal expansion causes the lid to expand making it easier to remove.
b. The heat chemically changes the glue around the edge releasing the lid from the jar.
c. The heat warms the jelly causing it to push the lid off the jar.
d. The heat makes the jar contract making it easier to remove.
Answer:
A, because as metal warms, it expands, and makes it easier to remove
Explanation:
^^
What is chemical energy?
A.the potential energy in chemical compounds that is waiting to be released
B.energy that is formed or caused by movement
C.the movement of diecrons throughout the world
D. Energy from the son or any other light source
4 ) which of the following is a true statement
5) what is true of all molecules based on the periodic table
a) they have electrochemical charges
b) they lack electrochemical charges
c) they have full outer electron shells
D) they contain at least one proton
Answer:
4:D 5:D
Explanation:
what is the formula for the ion potassium
Answer:
The formula for a Potassium ion is K+
Zinc reacts with lead (II) nitrate to produce zinc nitrate and lead. This reactions is:
Word form?
Answer:
Displacement Reaction
Explanation:
Zinc replaces lead in Lead(ll) nitrate as zinc is more reactive than lead.
If excess sodium sulfate react with 36 g of iron (III) phosphate and produce a 65.0% yield of sodium phosphate, how many grams of sodium phosphate are actually produced?
[tex]Na_2SO_4 + FePO_4[/tex] -> [tex]Na_3PO_4 + Fe_2(SO_4)_3[/tex]
Answer:
According to the stoichiometry, the theoretical yield is 11.5 grams. Multiplying this by 0.650, you get 7.48 grams.
Explanation:
7. Cecilia puts two magnetic toy trains very close to each other on a track. What will happen next, and
why.
What do you think is the primary reason why the Unionid mussel population declined whenever there is a dramatic increase in the Zebra mussel population?
Answer:
When the Zebra arrived they ate all the food so the Unionid mussels declined as they died from the lack of food. Causing the Zebra Zebra numbers to increase and Unionid numbers to decline.
When red copper wire is heated on a Bunsen burner flame, the surface of the copper turns black. The wrong statement below is
A. The surface of the red copper wire turns black because copper oxide
is formed.
B. The surface of the red copper wire turns black because copper is
reduced.
C. When the copper wire that has turned black is placed in dilute
sulphuric acid, blue colour can be seen in the solution
D. Mass is increased after the copper wire has turned black
Answer:
I think d is wrong statement