Answer:
Chopping wood logsA pot of water o a grate over a burning fireExplanation:
Physical change is easily reversible. Burning/combustion is a chemical process where substances react rapidly with oxygen: this is usually irreversible.
The marshmallow, roasted food and burned wood all undergo combustion and hence are tagged chemical changes.
I hope this helps.
Answer:
Chopping Wood
Heating Water
Explanation:
I need help with the 2nd part first gets brainlist
Answer:
7. 4H₂O
Elements: Hydrogen, Oxygen
Number of molecules: 4
Number of elements: 8 H, 4 O
Number of Atoms: 12
Explanation:
The elements are determined by the their symbol i.e. H = hydrogen.
The number of molecules is determined by the coefficient ( the number in front of everything, in this case 4).
The number of elements is determined by the coefficient and the subscripts. Multiply the coefficient by the subscript after each element. When there is no subscript, it is equal to 1. 4H₂ = 4x2 = 8; 4O = 4x1 = 4.
The number of atoms is all the individual elements added together. 8+4 = 12.
a molecule for sulfur dioxide consists of one sulfur atoms (S) and two oxygen atoms (0). what is the chemical formula for this compound
3.58 x 1023 molecules of propane C8H8 would occupy how much space at STP
Answer: At STP, a mole of gas takes up 22.4 Liters. The 22.4 Liters/mole quantity can be derived from the Ideal Gas Law, PV = nRT, plugging in STP conditions for P and T, and solving for V/n, which gets 22.4 Liters/mole.
Explanation:
A balloon is a sphere with a radius of 5.0 m. The force of air against the walls of the balloon is 45 N. What is the air pressure inside the balloon? Surface area = 12.56 × radius² 1 Pa = 1 N/m² How would I solve this problem? What are the steps or a good way to remeber how to solve?
Answer:
0.127 N/m² or 0.127 Pa
Explanation:
From the question given above, the following data were obtained:
Radius (r) = 5 m
Force (F) = 40 N
Pressure (P) =.?
Next, we shall determine the Surface area of the sphere (i.e the balloon). This can be obtained as follow:
Surface area = 12.56 × r²
Radius (r) = 5 m
Surface area = 12.56 × 5²
Surface area = 12.56 × 25
Surface area = 314 m²
Finally, we shall determine the pressure as follow:
Force (F) = 40 N
Surface area = 314 m²
Pressure (P) =.?
Pressure = Force /Area
Pressure = 40/314
Pressure = 0.127 N/m² = 0.127 Pa
Therefore, the pressure inside the balloon is 0.127 N/m² or 0.127 Pa.
True or False: A Precipitate is a solid
that forms out of a liquid solution as a
result of a chemical reaction
Answer:
true because it undergoes a tranformation
Explanation:
1 pc
Calculate the volume of a an object that has a height of 14.3cm, length or
25.2cm, width of 6.7cm. *
46.2cm
2414.412 cm
0.085 cm
53.785 cm
Answer:0.085
Explanation:
A total of eighteen electrons can be placed into the 3rd energy level.
Explain WHY?
Answer:
each principal energy level above the second contains, in addition to one s orbital and three p orbitals, a set of five d orbitals, called the d sublevel. The five d orbitals can hold up to 10 electrons. Thus, the third level holds a maximum of 18 electrons: 2 in the s orbital, 6 in the three p orbitals, and 10 in the five d orbitals.
Explanation:
colonel flanders makes boxes of chicken with various numbers of pieces. He charges $ 0.40 for each piece of chicken, plus a fixed charge of $ 0.55 for the box, the rolls, etc. If Iddy Ottic bought the $6.95 box, how many piecesof chicken should the box contain?
What explains the structure of metals and delocalized electrons?
A. the unit cell model
B. the geometric shape model
C. the covalent bond model
D. the electron sea model
Kinetic molecular theory states... (choose all that apply)
A. There is a chemical change when a solid melts to a liquid.
B. Particles that make up matter have kinetic energy.
C. Particles that make up matter are always in motion
Help it’s for a test!!!!!!!!!!!How many moles are in 2.16 x 1023 atoms of magnesium?
A. 35.9 moles
B. .359 moles
C. 7.18 moles
D. 0.359 moles
E. 0.90 moles
Rubbing alcohol or isopropanol can be described by the chemical formula C3H7OH. One milliliter of isopropanol has a mass of 0.76 g, so its density is 0.76 g/mL. Isopropanol is often used as a cleaner or a disinfectant and evaporates when placed on warm objects. However, caution must be taken when using isopropanol, because it is also highly flammable. Which of the following is a chemical property of isopropanol?
A. One mL of isopropanol has a mass of 0.76 g.
B. Isopropanol has a density of 0.76 g/mL.
C. Isopropanol evaporates when placed on a warm object.
D. Isopropanol is flammable.
A chemical property of isopropanol : D. Isopropanol is flammable.
Further explanationThere are changes that occur in the mater: physical changes and chemical changes
Classification uses the principle of the initial and final state of the substance.
Physical changes do not form new substances, so the properties of the particles remain the same.(size,volume,shape)
Example : boiling and freezing, just change its phase form from liquid to gas or from liquid to solid
Chemical changes/reaction form new substances(products) that are different from the initial substances(reactants)
Example : toxic, corroded
So :
the physical properties of isopropanol :mass, density, evaporation
the chemical properties of isopropanol :highly flammable
Answer:
D. Isopropanol is flammable.
Explanation:
Mass, volume, temperature, phase of matter, color, texture, density, and hardness are all examples of physical properties. However, flammability is an example of a chemical property.
Chemical properties describe an object's potential to change its chemical composition. These properties depend on the types of atoms found in the object and the arrangement of those atoms (and their subatomic particles).
What kinds of paintings did Winslow Homer make
Michelle learns in science class that simple machines such as an inclined plane can change the amount of force needed to lift heavy objects. She decides to test this with an experiment.
Michelle chooses a 10 kg weight. She sets up a ramp made of smooth metal that makes an angle θ with the floor. She attaches a spring scale to the weight and the top of the ramp in order to hold the weight in place. She records the force from the spring scale, then changes θ and records it again. She repeats this several times.
In this experiment, what is the dependent variable?
A.
the mass of the weight
B.
the angle θ between the ramp and the ground
C.
the amount of force on the spring scale
D.
the material the ramp is made of
Be fast please
What is the mass of an object with a density of 5.7 g/cm^3 and a volume of 48
cm^3? *
Answer:
273.6 g
Explanation:
mass =(density)(volume)
mass=(5.7g/cm^3 )(48 cm^3)
cancel out your cm^3 and your are left with grams
multiply (5.7g)(48)=273.6 g
The mass of an object with a density of 5.7 g/cm³ and a volume of 48 cm³ is 273.6 grams.
What is density?Density is defined as the degree to which a material is packed together.
It is also defined as a mass per unit volume of the substance.
Its SI unit is kilogram per cubic meter or gram per meter.
Density can be expressed as
Density = mass / volume
Mass = density x volume
As given, Density = 5.7 g/cm³
Volume = 48 cm³
So, Mass = 5.7 g/cm³ x 48 cm³
= 273.6 grams
Thus, the mass of an object with a density of 5.7 g/cm³ and a volume of 48 cm³ is 273.6 grams.
To learn more about density, refer to the link below:
https://brainly.com/question/15164682
#SPJ5
What is the atomic number of an atom?
O the number of neutrons
O the number of electrons and neutrons
O the number of protons
the number protons and neutrons
Which of the following best describes how Thomson
concluded that electrons are present in all atoms.
a
The charge-to-mass ratio of electrons is always the
same constant, no matter which substances are
used in the cathode ray tube.
b The cathode ray was able to turn a wheel.
The cathode ray always bent toward a negatively
charged plate.
d
The charge-to-mass ratio is unique to each different
element.
Answer: A
Explanation:
The charge-to-mass ratio of electrons is always the same constant, no matter which substances are used in the cathode ray tube.
Explanation:
Thomson in his model of atom discussed that the atom consists of a negative charge particle termed electron randomly distributed in the positively charged sphere to balance the negative charge.His model of the atom was also known as the Plum pudding model of the atom. In which electrons are embedded in positive soup.He discovered electrons by conducting an experiment with cathode rays in which cathode rays emerging from the cathode were observed to be deflected towards the positively charged plate.He also conducted the same experiment with different metals (for anode and cathode) and gases and found out that the charge to mass ratio of the electron was regardless of the metals or gases used in the experiment.With this, he landed on the conclusion that these particles of cathode rays are the universal component of matter.So, from this, we can conclude that the charge-to-mass ratio of electrons is always the same constant, no matter which substances are used in the cathode ray tube describes Thomson's conclusion that electrons are present in all atoms.
Learn more about J.J. Thomson's model of atom here:
brainly.com/question/2437167?referrer=searchResults
brainly.com/question/1874920?referrer=searchResults
What is the mass of 4.39 mol Na?
Answer:
101 g Na
Explanation:
To convert between moles and grams, you have to use the molar mass of the substance. The molar mass of sodium is 22.99 g/mol. You use this as the unit converter.
[tex]4.39molNa*\frac{22.99gNa}{1molNa} = 100.9261gNa[/tex]
Round the number to the lowest number of significant figures; 101 g Na.
The mass of 4.39 moles of sodium (Na) is 100.97grams.
HOW TO CALCULATE MASS:The mass of a substance can be calculated by multiplying the number of moles in the substance by its molar mass. That is;Mass = no. of moles × molar mass
According to this question, there are 4.39 moles of Na. The molar mass of Na is 23g/mol.Mass of Na = 4.39 × 23
Mass of Na = 100.97grams.
Therefore, mass of 4.39 moles of sodium (Na) is 100.97grams.
Learn more about mass calculations at: https://brainly.com/question/8101390
Would love some help pleaseee. and please at least read the question instead of skipping it please.
Measuring tools can have errors. Errors lead to ___________________ results and _______________ conclusions. To calculate the difference of the accepted value and the experimental value, scientists use this formula:
percent error = (experimental value − ) × 100. accepted value
Minimizing Bias
People show bias when they want everyone to accept their results. Bias can arise for many reasons:
• Companies show bias when they depict only the research details that are in the best interest of their ____________.
• Scientists may be biased toward their _____________ and modify results suit their needs.
• Scientists may also show to bias get their research published in ______________ ______________.
Such biases often lead to _______________ facts. An important part of scientific thinking is identifying biases and taking the necessary steps to minimize them.
For results to be considered scientifically accurate, any scientist, regardless of his or her own bias, should be able to replicate the experiment and get the same results.
Summary
Think of some studies you’ve heard about. How can you tell whether the studies were well-designed and scientifically accurate or had biases?
Answer: this looks like your homework
Explanation:if you want help you are going to have to ask a specific question instead of giving people your homework.
Answer:
Honestly I would search this up maybe there might be a pdf with the answers. Sorry chemistry isn't my thing:(
Explanation:
What is force and motion
Answer:
In physics, a force is any interaction that, when unopposed, will change the motion of an object. A force can cause an object with mass to change its velocity (which includes beginning moving from a state of rest), i.e., to accelerate. Force can also be described intuitively as a push or a pull.
lol
Which types of matter are made of atoms
a. Mixtures
b. Elements
C. Compounds
D. All of the above
Answer:
D all above yes I think it's all above
Answer: D
Explanation: All of the above.
Plz mark brainliest:)
What is Arsenic cost per unit?
Answer:
arsenic costs $320 per 100g
Explanation:
When many earthquakes are studied, there is another common pattern that emerges: a "Shadow Zone". This is an area, for any earthquake, on the Earth where direct S-waves don't arrive at all and P waves are refracted. What do you think causes these P waves to be refracted? *
Answer:
Sudden decrease in the velocity at the boundary.
Explanation:
The shadow zone is the zone of the earth from angular distances of 104° to 140° from a known earthquake that does not directly receive any P waves. Now, this shadow zone occurs as a result of S waves getting stopped completely by the liquid core and the P waves being refracted by the liquid core.
From earlier seismic discoveries, this boundary which is the shadow zone that does not directly receive any P-waves was found to be due to the fact that the P-waves were refracted inwards as a result of the sudden decrease in velocity at the boundary.
How many moles are in 12.6 grams of K2S?
25 cm of liquid 'A' and 20 cm of liquid
'B' are mixed at 25°C and the volume of
solution was measured to be 44.8 cm3
then correct reaction is
(A) A Hmix = 0, solution shows
ideal
Answer:
The correct option is;
(B) [tex]\Delta H_{mix} < 0[/tex], solution shows negative deviation
Explanation:
The given parameters are;
The available volume of liquid A = 25 cm³
The available volume of liquid B = 20 cm³
The volume of the solution (mixture) = 44.8 cm³
Therefore, we have;
[tex]\Delta _{mix} V < 0[/tex]
Which is one of the prerequisite for the formation of negative deviation
When a non-ideal solution shows negative deviation according to Raoult's Law, we have;
[tex]\Delta _{mix} H < 0[/tex], we have more heat released due to new molecular interactions.
Which statement best explains why the air pressure is greater at the poles than at the equator
Answer:
At the equator, the altitude is lower, and also because of the direct heating of sun rays on the surface, the temperature is much higher than at the poles. This makes the air near the surface hot and lighter and hence it rises up which results in lower air pressure.
Explanation:
Plz give me brainliest .-.
stages of mitosis in order
Answer:
nucleus formed
prophase
metaphase
anaphase
telophase and cytokinesis
Identify the property of the matter described below.
Alcohol floats on top of the water.
A-pH
B-conductivity
C-density
D-luster
Answer: C.
Explanation: Alcohol floats on oil and water sinks in oil. Water, alcohol, and oil layer well because of their densities, but also because the oil layer does not dissolve in either liquid. The oil keeps the water and alcohol separated so that they do not dissolve in one another. ... Water sinks because it is more dense than oil.
Which of the following is the correct model of C7H16?
A.
B.
C.
D.
Answer:
D
Explanation:
Option D gives the correct model of C7H16. From the option, one will discover that the model has 7 carbons in the backbone. If you count the attached hydrogen, you will discover that the hydrogen is 16 in total.
This model or skeletal structure of this element represents heptane. Heptane or n-heptane is known to be a straight-chain compound and an alkane. It's chemical formula can also be written as: H₃C(CH₂)₅CH₃ or C₇H₁₆.
This compound is known to be one of the main components of gasoline. It is known to be a volatile organic compound and a clear and colorless liquids with a petroleum-like odor.
Answer: D
Explanation: Just took the test
How do I do this problem???
Answer:
i believe it's c
Explanation:
my reason is that if you look at the electrons 2 is the most comm