Answer:
d = 0.84 g/cm³
Explanation:
Given data:
Mass of wood = 2.85 g
Volume of water = 20.0 mL
Volume of water + wood = 23.4 mL
Density of wood = ?
Solution:
Volume of wood = (Volume of water + wood ) - Volume of water
Volume of wood = 23.4 mL - 20.0 mL
Volume of wood = 3.4 mL
1 mL = 1 cm³
Density of wood:
d = m/v
d = 2.85 g / 3.4cm³
d = 0.84 g/cm³
How many molecules are in 23 moles of oxygen (O2)? Round the answer to one digit past the decimal point. If the answer is less than 1, you must type a zero before the decimal point.
To Find :
How many molecules are in 23 moles of oxygen (O₂).
Solution :
We know, 1 mole of any atom/molecule contains 6.022 × 10²³ numbers of atoms/molecules.
So, number of molecules in 23 moles of O₂ are :
[tex]n= 23\times 6.022\times 10^{23}\\\\n =138.506\times 10^{23}\\\\n = 1.385 \times 10^{25}\ molecules[/tex]
Hence, this is the required solution.
equation for the complete combustion of a hydrocarbon fuel.
Answer:
the general equation for complete combustion reactions is fuel + O2 __ Co2 + H2O .Which statement best describes what happens when a person sees an orange t-shirt?
The t-shirt absorbs orange light from human eyes.
Human eyes reflect orange light back to the t-shirt.
Orange light reflected from the t-shirt enters human eyes.
Orange light absorbed by the t-shirt is perceived by the human eyes.
Answer:
The correct answer is - Orange light reflected from the t-shirt enters human eyes.
Explanation:
Human eyes and brain are altogether able to detect the color of the object by translating the light which is reflected by the object and transmitted by the light receptors in the eyes ad brain translate light to color.
The objects are able to absorb some colors and reflect others on the basis of their wavelength, The reflected colors are detected by our eyes and brain and objects appear to be a particular color. like here, the orange color is reflected by the t-shirt and enters in human eyes.
Answer:
its c
Explanation:
A 2.50 g sample of zinc is heated, then placed in a calorimeter containing 65.0 g of water. Temperature of water increases from 20.00 oC to 22.50 oC. The specific heat of zinc is 0.390 J/goC. What was the initial temperature of the zinc metal sample? (final temperatures of zinc and water are the same)
Answer:
719.83°C
Explanation:
The heat that the sample of Zinc gives is equal to the heat that water is absorbing. That is:
C(Zn) * m(Zn) * ΔT(Zn) = C(H2O) * m(H2O) * ΔT(H2O)
Where:
C is specific heat (Zn: 0.390J/g°C; H2O: 4.184J/g°C)
m is mass (Zn: 2.50g; H2O: 65.0g)
ΔT (Zn: ?; H2O: (22.5°C - 20.0°C = 2.50°C)
Replacing:
0.390J/g°C * 2.50g * ΔT(Zn) = 4.184J/g°C * 65.0g * 2.50
ΔT(Zn) = 697.33°C
As final temperature of Zn is 22.50°C, initial temperature is:
Initial temperature: 697.33°C + 22.50°C
719.83°C
What is oxidized in a galvanic cell made with silver and nickel electrodes?
A. The silver metal
B. The nickel metal
C. The nickel ions
D. The silver ions
Answer:
B. The nickle Metal
Explanation:
A P E X
Use the drop-down menus to answer the questions.
As the amount of surface area increases, what happens to the rate of this reaction?
If the antacid tablet were broken into eight pieces, what would be a reasonable estimate for the time of reaction?
Answer:
the rate is faster, and the time of reaction is 28 seconds
Explanation:
i did the test
Answer:
The rate is faster, 28 seconds
Explanation:
If an atom has an atomic mass of 19 and an atomic number of 9, how many protons, neutrons and electrons does it have?
Answer:
protons = 9
neutrons = 10
electrons = 9 because it is neutral atom
Explanation:
atomic number= protons = 9
atomic mass= protons + neutrons
19= 9 + n
n= 10
Where are people exposed to chemicals?
O A. Mostly in public buildings
O B. Only in the home
C. Mostly outside
O D. Everywhere
Answer:
I believe the correct answer is D.
Explanation:
You are breathing in dinitrogen and dioxygen. You exhale dinitrogen and carbon dioxide. And the atmosphere contains traces of other gases. You drink water. You have a wash with water, and soap. You eat carbohydrates and proteins. You ride to work on a vehicle powered by hydrocarbons, which spits out carbon dioxide exhaust fumes, and also some nitrogen oxides. And so your exposure to chemicals is pervasive, and unavoidable.
Answer:
d
Explanation:
what are two ways pollution can get in water
One of the most polluting being city sewage and industrial waste discharge. Indirect sources of water pollution include contaminants that enter the water supply from soils or groundwater systems and from the atmosphere via rain.
Answer:
gas gets dumped is one and the other is dumping trash into water
Explanation:
I need help with number 3
the equation is 4Al+3O2=2Al2O3
Which process has the minimal effect on heating our atmosphere?
1.Conduction,
2.Convection,
3.Radiation
Answer:
Radiation you're welcome <3
Identify each of the following types of compounds as Binary Ionic, Ternary Ionic, Binary Acids, or Oxyacids.
1) K2HPO4
2) H2CO3(aq)
3) (NH4)3P
4) Na2O2
5) Hg(NO2)2
6) Al(ClO2)3
Answer:
the words to identify them is them in kaps right
Explanation:
I need help asap, thank you.
Answer: Answer to your question is B. I did a science
Explanation: Test was to see which would dissolve fastest...
Which of the following is a heterogeneous mixture?
A. Oil and Vinegar
B. Air
C. Milk
D. Vinegar in water
Answer:
B
Explanation:
b/c air is not seen by eye
Will mark you as brainiest!
Aluminum has the larger atomic radius.
silicone is larger than carbon.
Aluminum is larger than silicon
I think silicon is the answer
1 point
Sulfur (S) Oxygen (02) water (H2O) and Sodium Chloride (NaCl) are all
examples of pure substances. Which of the following describes all pure
substances *
A pure substance cannot be broken down into simpler substances
O A pure substance consists of only one element
A pure substance has a definite chemical composition
A pure substance is normally found as a solid in room temperature
Answer:
A pure substance has a definite chemical composition
A pure substance has a definite chemical composition in all states. Pure substance can be composed of multiple elements but the composition does not alter in any case.
What are pure substances ?Pure substances are formed either a single component or a combination of more components with a definite composition forming a single phase. Unlike mixtures a pure substance cannot be separated into its components physically.
For example pure water is a pure substance. Water is formed from hydrogen and oxygen atoms in a definite proportion forming a molecular compound that does not alter anyway.
However, salt solution, mixture of two gases etc. are not pure substance. They haven't a definite composition and can be separated by some physical methods. Hence, option c is correct.
Find more on pure substances:
https://brainly.com/question/24462192
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Predict the products for a reaction between the following:
Ca (s) + AgNO3 (aq) -->
Answer:
Ca + AgNO3 ---> Ca(NO3)2 + Ag
Calcium + silver nitrate ---> Calcium nitrate + silver
also ...reaction type is Single displacement reaction .
hope this answer's your question.
PLEASE HELP ASAPPP
A cylinder shaped water tank has a height of 212 ft (6461.76 cm), and is able
to hold 15,000 gallons of water (15,000,000 mL or 15,000,000 cm3). The
volume of a cylinder is expressed by the equation
V = tr^2h
Where V is the volume, r is the radius, and h is the height of the cylinder.
Express the radius (r) in terms of volume (V) and height (h), then determine
the radius of a cylinder water tank (in centimeters) that is filled to capacity.
Answer:
r = [tex]\sqrt{\frac{v}{\pi h} }[/tex]
27.2cm
Explanation:
Given parameters:
Height of tank = 6461.76cm
Volume of water = 15000000cm³
Volume of cylinder = [tex]\pi[/tex] r² h
i. Express radius in terms of volume;
we are to make radius the subject of the expression;
v = [tex]\pi[/tex] r² h
divide both sides by πh
[tex]\frac{v}{\pi h}[/tex] = [tex]\frac{\pi r^{2}h }{\pi h }[/tex]
r² = [tex]\frac{v}{\pi h}[/tex]
r = [tex]\sqrt{\frac{v}{\pi h} }[/tex]
ii.
Radius of the water tank;
r = [tex]\sqrt{\frac{15000000}{\pi x 6461.76} }[/tex] = 27.2cm
PLEASE HELP ME!! THIS IS DUE SOON!!
Determine the number of H2O molecules in 837.4 g of H2O.
Answer in units of molec.
Answer:
Divide 837.4 g by 18.015 g/mol to get moles of H2O
Multiply moles of H2O by 6.022 x 10^23 molecules/mol to get molecules (of H2O in 837.4 g)
Round off your final answer to 4 sig figs.
Thank you and please rate me as brainliest as it will help me to level up
Help :) For 100 points
Answer:
6. Color Change.
Production of an odor.
Change of Temperature.
Explanation:
That is the only one I know :)
Answer:
6. 3 things could potentially be, a change in mass, a change in color, or a change in weight. obviously there are more, but these are 3.
I'm sorry I couldn't answer more of these question of yours, I don;t know too much about aluminium :/
May I have brainliest please? :)
a motorcycle is moving along a road for a distance of 20KM. After 2 hours what is it's the average speed?
Answer:
If it took the motorcycle 2 hours to cover 20km, then the average speed is 10km per hour.
Explanation:
Speed is equal to distance over time. So 20km divided by 2 hours is 10 km per hour.
Please mark brainliest!!! Thanks.
Answer:
96.56063 km/h
Explanation:
Which chemical formula shows an ionic compound?
NaCl
CO2
C6H12O6
N2O
Answer:
NaCl
Explanation:
The only chemical species that shows an ionic compound is NaCl.
NaCl is an ionic compound that conducts electricity in molten state due to presence of free mobile electrons in the structure when molten.
An ionic bond typically forms between a metal and non-metal. In the compound NaCl, Na is the metal and Cl is the non-metal. The difference in electronegativity allows for this bond type to form.Answer:
it is A i took the test could i have the crown please
Explanation:
Which metal is not required to have its charge specified with roman numerals in the names of ionic compounds it forms?
Which one is idk what it is giving brainliest
Answer:
B or C
Explanation:
I don't really know sorry.
Answer:
D
Explanation:
I think D I also took the test.
10. Anna wants to measure the water temperature in the pail. What instrument
she needs to use?
A. Thermometer
C. Barometer
B. Speedometer
D. Anemometer
please answer me
Answer: A. Thermometer
Explanation:
A thermometer is used to measure temperature , while the others measure different things.
What is the mass, in grams, of 9.01 x 1024 molecules of methanol (CH, OH) ?
Answer:
480.6 g
Explanation:
Given data:
Number of molecules of methanol = 9.01 ×10²⁴
Mass in gram = ?
Solution:
The given problem will solve by using Avogadro number.
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.
The number 6.022 × 10²³ is called Avogadro number.
1 mole = 6.022 × 10²³ molecules
9.01 ×10²⁴molecules ×1 mol /6.022 × 10²³ molecules
1.5 ×10¹ mol
15 mol
Mass in gram:
Mass = number of moles × molar mass
Mass = 15 mol × 32.04 g/mol
Mass = 480.6 g
HELP ASAP I NEED HELP FAST PLEASE
Kinetic energy is often referred to the energy of
Question 1 options:
A)work
B)mass
C)motion
D)force
)
Question 2 (1 point)
Saving...
Which example has the least kinetic energy
Question 2 options:
A)a 10 kg rock rolling down a hillside at 100 m/s.
B)a 100 kg rock rolling down a hillside at 100 m/s.
C)a 1 kg rock rolling down a hillside at 1 m/s.
D)a 100 kg rock rolling down a hillside at 1 m/s.
Question 3 (1 point)
Saved
The law of conservation of energy states that
Question 3 options:
energy can be created but not destroyed.
energy can neither be created nor destroyed, only change forms.
energy can be destroyed but not created.
Question 3 (1 point)
Saved
The law of conservation of energy states that
Question 3 options:
A energy can be created but not destroyed.
B energy can neither be created nor destroyed, only change forms.
C energy can be destroyed but not created.
D energy never changes
Which is an example of an object increasing its kinetic energy
Question 4 options:
A a train stopped at the station.
B an airplane after landing on a level runway.
C a mouse running faster after spotting a cat.
D a rocket before launch.
Question 5 (1 point)
Identify when an object has a kinetic energy of zero joules.
Question 5 options:
A when an object is no longer in motion.
B when the energy has been destroyed.
C just after a ball it leaves your hand pitching a ball.
D as a pendulum swings downward.
Which is NOT an example of kinetic energy
Question 6 options:
A an elevator moving up to the 3rd floor.
B a skateboard rolling down a hill.
C an arrow after it has hit the target and is at rest.
D a skydiver as they decrease speed after opening their parachute.
1. C
2. D (I’m not entirely sure)
3.energy can neither be created nor destroyed, only change forms.
4. C
5. A
6. C
I’ve researched and tried to answer these questions correctly.
Answer:
1.c
2.a
3.created or destroyed
4.c
5.a
6.c
Explanation:
thanks me later
What field(s) does a moving electron have?
ОА.
electric and gravitational fields
OB. magnetic and gravitational fields
OC. gravitational, electric, and magnetic fields
OD.
electric field only
Answer:
electric field or magnetic field both are same
Explanation:
in an electromagnet the movement of electrons in a wire creates the magnetic field.an electromagnet and the permanent magnet both the magnet have the magnetic fields that can attract the same kinds of materials.
what is an atomic mass unit?
Answer:
A unit of mass used to express atomic and molecular weights, equal to one-twelfth of the mass of an atom of carbon-12. It is equal to approximately 1.66 x 10-27 kg.
Explanation:
Answer:
a unit of mass used to express atomic and molecular weights, equal to one-twelfth of the mass of an atom of carbon-12. It is equal to approximately 1.66 x 10-27 kg.
Explanation:
hope it helps, mark brainliest please
In acidic solution. A 70.0 mL sample of a solution containing Fe2+ requires 70.0 mL of a 0.150 M KMnO4 solution for complete reaction. What is the concentration of the Fe2+ in the original solution?
Answer:
0.75M Fe²⁺
Explanation:
First, we need to balance the redox reaction in acidic medium. Then, we can obtain moles of KMnO4 and with the reaction moles and molarity of the Fe²⁺ solution:
Redox Balance:
Fe²⁺ → Fe³⁺ + 1e⁻
5e⁻ + 8H⁺ + MnO₄⁻ → Mn²⁺ + 4H₂O
___________________________
5Fe²⁺ + 5e⁻ + 8H⁺ + MnO₄⁻ → 5Fe³⁺ + 5e⁻ + Mn²⁺ + 4H₂O
5Fe²⁺ + 8H⁺ + MnO₄⁻ → 5Fe³⁺ + Mn²⁺ + 4H₂OMoles of KMnO₄:
70.0mL = 0.0700L * (0.150mol / L) = 0.0105 moles KMnO₄
Moles and molarity Fe²⁺:
0.0105 moles KMnO₄ * (5 moles Fe²⁺ / 1mol KMnO₄) = 0.0525 moles Fe²⁺
In 70.0mL = 0.0700L:
0.0525 moles Fe²⁺ / 0.0700L =
0.75M Fe²⁺