Answer:
The difference between a physical reaction and a chemical reaction is composition. In a chemical reaction, there is a change in the composition of the substances in question; in a physical change there is a difference in the appearance, smell, or simple display of a sample of matter without a change in composition. Although we call them physical "reactions," no reaction is actually occurring. In order for a reaction to take place, there must be a change in the elemental composition of the substance in question. Thus, we shall simply refer to physical "reactions" as physical changes from now on.
Introduction
Physical changes are limited to changes that result in a difference in display without changing the composition. Some common changes (but not limited to) are:
Texture
Color
Temperature
Shape
Change of State (Boiling Point and Melting Point are significant factors in determining this change.)
Physical properties include many other aspects of a substance. The following are (but not limited to) physical properties.
Luster
Malleability
Ability to be drawn into a thin wire
Density
Viscosity
Solubility
Mass
Volume
Any change in these physical properties is referred to as a physical change. For further information, please refer to Properties of Matter.
Chemical changes, on the other hand, are quite different. A chemical change occurs when the substance's composition is changed. When bonds are broken and new ones are formed a chemical change occurs. The following are indicators of chemical changes:
Change in Temperature
Change in Color
Noticeable Odor (after reaction has begun)
Formation of a Precipitate
Formation of Bubbles
Note: When two or more reactants are mixed and a change in temperature, color, etc. is noticed, a chemical reaction is probably occurring. These are not definite indicators; a chemical reaction may not be occurring. A change in color is not always a chemical change. If one were to change the color of a substance in a non-chemical reaction scenario, such as painting a car, the change is physical and not chemical. This is because the composition of the car has not changed. Proceed with caution.
helpppppppp meeeeeee
Answer:
Synthesis
General Formulas and Concepts:
Chemistry - Reactions
Synthesis Reactions: A + B → AB Decomposition Reactions: AB → A + B Single-Replacement Reactions: A + BC → AB + C Double-Replacement Reactions: AB + CD → AD + BCExplanation:
Step 1: Define RxN
RxN: NH₃ + H₂SO₄ → (NH₄)₂SO₄
Step 2: Identify
Combining 2 compounds to form 1.
NH₃ + H₂SO₄ → (NH₄)₂SO₄
A + B → AB
It is a Synthesis Reaction.
pleasee help ASAP
will mark brainliest!
Answer:
question 1- is B
question 2- is A
*I hope this helps you guys out!
Which of the following correctly describes the electrical charges of subatomic particles?
B Protons/positive; neutrons/negative; electrons/negative
C Protons/neutral; neutrons/positive ; electrons/negative
D Protons/negative; neutrons/neutral; electrons/negative
Answer:
D Protons/negative; neutrons/neutral; electrons/negative
Explanation:
There are three fundamental subatomic particles found in atom which are the protons, neutrons and electrons.
Protons are the positively charged particlesNeutrons are neutral and do not carry any chargesElectrons are negatively charged.In the tiny central nucleus, both protons and neutrons can be found
The electrons occupy the bulk volume of the atom.
Which of the following is a CHEMICAL CHANGE?
A- Buttering Toast
B- Melting ice Cream
C-An egg gives off a rotten smell
D-sugar is dissolved into water
E- baking soda mixed with vinegar forms bubbles
F- boiling water forms bubbles
G-Iron turns red as it rusts
H-Iron turns red as it is heated
Answer:
G, but I think that theres more than one answer
Write the group number using both A/B and 1-18 notation for elements that have the
following outer electron configuration:
a 252
b. 3523p3
c. 4s23
d. 5524d105p4
Fill in the blanks with the correct words.
The movement of molecules from an area of low concentration to an area of high concentration occurs in help plz in being timed I’ll mark u Brainlyest
transport.
transport, molecules move from an area of high concentration to an area of low concentration.
In
Intro
Done
Answer:
i had this same question and the answer is electron.
Explanation:
How much heat is required to raise the temperature of a 6.21 g sample of iron from 25.0 oC to 79.8 oC?
Answer:
151.1J
Explanation:
Given parameters:
Mass of iron = 6.21g
Initial temperature of iron = 25°C
Final temperature of iron = 79.8°C
Unknown:
Amount of heat = ?
Solution:
The amount of heat require to cause this temperature can be determined using the expression below;
H = m c (T₂ - T₁)
H is the amount of heat
m is the mass
c is the specific heat capacity
T is the temperature
Specific heat capacity of iron 0.444J/g°C
Insert the parameters and solve;
H = 6.21 x 0.444 x (79.8 - 25)
H = 151.1J
How many atoms are there in 4.50 moles of Ba(NO^2)2
Answer:
There are 1031.85 grams in 4.50 moles of Ba(NO2)2
Explanation:
m = 4.50 × 229.3 = 1031.85
Help easy valence electrons question (picture)
Answer:
4,7,2
Explanation:
Count the amount of electrons on the outer shell on each question.
a. 4 valence electrons
b. 7 valence electrons
c. 2 valence electrons
When was Quartz found and how is it extracted??
Answer:
Quartz was discovered in 1880 and they use buldozers and backhoes (to remove dust/dirt around it) and rarely explosives.
Explanation:
An unknown substance is an excellent electrical conductor in the solid state and is malleable. What type of chemical bonding does this substance exhibit
Answer:
Ionic bonds
Explanation:
Is nitrogen reactive or stable?
A reactive
B stable
Nitrogen is reactive I think
Two students made the Lewis dot diagrams of NH3. The diagrams are as shown. Two visual diagrams of an N H three molecule are shown. Student As diagram on the left has nitrogen at the center and connects with each hydrogen atom by an arrow pointing away from the nitrogen, one below, one on the right, and one on the left. There is a pair of dots above the nitrogen atom. Student Bs diagram on the right has nitrogen at the center connecting by a straight line to each hydrogen positioned below, to the left, and to the right of nitrogen. There is a pair of dots above the nitrogen atom. Which student drew the correct Lewis dot diagram? Only Student A Only Student B Both Student A and Student B Neither Student A nor Student B
Answer:
Only Student A
Explanation:
The first thing to consider in the diagrams of student A and B is to be sure that that the diagrams obey the octet rule and represent the written formula of ammonia (NH3). Clearly, only the diagram drawn by student A satisfy the these conditions.
If we look at the both diagrams closely, we will discover that the diagram drawn by student B does not satisfy the octet rule nor the trivalency of nitrogen even though it shows the lone pair of electrons on nitrogen hence it can not be the correct dot electron structure for NH3.
Answer: It is neither A or B
Explanation: I took the test and got this correct. Many people are saying only B, but that is wrong.
( please give brainliest :) )
K20
Molar Mass (g/mole)
2(39.10) + 16.00 = 94.20 g/mole
Moles
5.85 moles
Mass (grams)
Particles
Answer:
yes
Explanation:
that is the answer
Air that has been removed from a bell jar will NOT allow _____________ waves to travel through the jar. Question 4 options: sound light water
Answer:
Sound.
Explanation:
Sound requires a medium such as air to travel.
How can air quality be fine on one day and hazardous on the next? What
are some things that can cause a rapid change in air quality? *
Answer:
Air Current
Explanation:
Say I am in California and there is a massive fire next to me but not close enough to me to really see the fire and the next day I see no fire but theres a ton of ash in the sky, this can be due to the wind current taking the smoke from the fire into my direction and that smoke falling in my area. So basically a wind current can take the smoke from a fire into another destination and cause a rapid change in air quality in a day.
Plz help me answer this!!
Answer:
cellular respiration and photosynthesis :)
Answer:
1.) Cellular Respiration (2.) Photosynthesis
Explanation:
Oxygen (O2) is a reactant in the process of cellular respiration and a product of photosynthesis.
Which of the following subatomic particles are found surrounding the nucleus and have a negative charge?
F negatrons
G neutrons
H protons
J electrons
Answer:
J electrons
Explanation:
Electrons are the negatively charged subatomic particles that surrounds the nucleus of an atom.
Electrons occupy the bulk volume of an atom. These particle was discovered by J.J ThomsonThey found orbiting the extra-nuclear space of every atom. The nucleus is made up of protons and neutrons.James is trying newton's 2nd law of motion he tries to move four different objects with different Mass, Shape, and size from point a to point b. A toy car, a car kitchen table, and a refrigerator. what is the object that takes the most force to move
Answer:
By Newton's laws. we know that when we apply a force in an object, then we also are applying acceleration, given by the equation F =ma, where F is the applied force, m is the mass of the object and a is the acceleration.
Now in this problem, we only have that James want to move objects from point A to point B. If the problem says that James does it at the same time for each object, then we could assume that each object has the same acceleration A.
F = m*A
then if the mass of the o
object increases, the force needed to move it at the given acceleration will increase also, then the object that requires less force is the object with less mass, in this case, the toy car.
But in this problem never says that the objects are moved with the same acceleration (or in the same amount of time), then we could apply the same force in the four objects and eventually the four will get to the point b ( for example, the refrigerator would take a lot more of time than the toy car.
Answer:
it's c, the toy car.
Explanation:
1.Which statement(s) is/are true about a divergent plate boundary? Check all that apply.
A.new crust is created here
B.an ocean trench is found here
C.a rift valley is associated with this boundary
D.subduction occurs at this boundary
E.a mid-ocean ridge is found at this boundary
F.San Andreas is an example of this type of boundary
G.sea floor spreading occurs here
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2.Which statement(s) is/are true about a transform plate boundary? Check all that apply.
A.an ocean trench is found here
B.earthquakes frequent this boundary
C.subduction occurs at this boundary
D.two plates are sliding past each other
E.San Andreas is an example of this type of boundary
F.an ocean trench is found here
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3.Which statement(s) is/are true about a convergent plate boundary? Check all that apply.
an ocean trench is found here
a rift valley is associated with this boundary
subduction occurs at this boundary
volcanic island chain might occur here
folded mountains might form here
earthquakes might occur here
San Andreas is an example of this type of boundary
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SINCE THIS IS ALOT OF THINKING I AM GIVING A GOOD AMOUT OF POINTS.....
PLEASE DONT SCAM AND STEAL THE POINTS
Answer:
I know the first one is c or e but i not sure what the others are, the second one is- wait are you sure your in 6th grade lol? I dont remember learning this
Answer:
OMG ITS MEHH
Explanation:
Asbestos is a fibrous silicate mineral with remarkably high tensile strength.But it is no longer used because airborne
asbestos particles can cause lung cancer. Grunerite, a type of asbestos, has a tensile strength of 15 x 102 kg/mm2 (thus, a strand of grunerite with a 1-mm2 cross-sectional area can hold up to 15 x 102 kg). The tensile strengths of aluminum and Steel No. 5137 are 25 x 104 Iblin2 and 5.0 x 104 Iblin2, respectively. Calculate the cross-sectional area (in mm2) of wires of aluminum and of Steel No. 5137 that have the same tensile strength as a fiber of grunerite with a cross-sectional area of
1.0 micro.mZ
Answer:
Area of aluminum = 8.53 * 10⁻⁶ mm²
Area of steel = 4.27 * 10⁻⁶ mm²
Explanation:
1 in² = 645.16 mm²
1 lb = 0.453592 kg
Tensile strength of Grunerite = 1.5 * 10² kg/mm²
Tensile strength of aluminum = 2.5 * 10⁴ lb/in²
Tensile strength of aluminum = 2.5 * 10⁴ * (0.453592 kg/lb /645.16 mm²/in²)
Tensile strength of aluminum = 17.58 kg/mm²
Tensile strength of Steel No. 5137 = 5.0 * 10⁴ lb/in²
Tensile strength of Steel No. 5137 = 5.0 * 10⁴ * (0.453592 kg/lb /645.16 mm²/in²
Tensile strength of Steel No. 5137 = 35.15 kg/mm²
Area of Grunerite = 1.0 μm² = 10⁻⁶ mm²
Mass of Grunerite = area * tensile strength
mass of Grunerite = 10⁻⁶ mm² * 1.5 * 10² kg/mm² = 1.5 * 10⁻⁴ kg
Area of aluminum of same tensile strength as Grunerite = mass of Grunerite/ tensile strength of aluminum
Area of aluminum = 1.5 * 10⁻⁴ kg / 17.58 kg/mm²
Area of aluminum = 8.53 * 10⁻⁶ mm²
Area of Steel No. 5137 of same tensile strength as Grunerite = mass of Grunerite/ tensile strength of aluminum
Area of steel = 1.5 * 10⁻⁴ kg / 35.15 kg/mm² = 8.53 * 10⁻² mm²
Area of steel = 4.27 * 10⁻⁶ mm²
1. Matter is described by its properties which are:
a. the characteristics of a substance that make it similar to others
b. the characteristics of a substance that make it unique
c. the amount of houses it owns
d. anything that takes up space
2. Physical properties that we use to describe matter are:
a. mass, weight, volume and density
b. color, mass, weight, and density
c. density, mass, size and smell
d. mass, scale, volume and density
3. Mass is how _______ is in an object
a. much matter
b. much weight
c. much atoms
d. all of the above
4. The mass of an object remains constant, but its weight may change depending on:
a. the number atoms
b. the volume
c. the density
d. gravitational pull
5. Density can be described as:
a. the number atoms in an objects mass
b. the volume of an object plus its mass
c. the amount of mass in a given volume
d. something similar to weight
you dont have to answer them all. whatever you can do is fine
Answer:
3=a 5=b 4=d 2= b yea that's pretty much the answers
In chemistry class, Allen determined the effectiveness of various metals in releasing hydrogen gas from hydrochloric acid. Several weeks later, Allen read that a utilities company was burying lead next to iron pipes to prevent rusting. Allen hypothesized that less rusting would occur with the more active metals. He placed the following into 4 separate beakers of water: (a) 1 iron nail, (b) 1 iron nail wrapped with an aluminum strip, (c) 1 iron nail wrapped with a magnesium strip, and (d) 1 iron nail wrapped with a lead strip. He used the same amount of water, equal amounts (mass) of the metals, and the same type of iron nails. At the end of 5 days, he rated the amount of rusting as small, moderate, or large. He also recorded the color of the water. What is the independent variable?
a) the amount of water
b) the metals strips
c) amount of rust
d) hydrochloric acid
Answer:
b) the metals strips
Explanation:
In an experimental design, an independent variable is a variable that is changed or manipulated in a series of experiments. An independent variable is not dependent on any other variable in the experiment. The hypothesis for this experiment is stated to be: "If the chemical activity of the metallic wrapper is increased, then less rusting of iron will occur. The independent variable relates to the type of metal wrapping strip, and the dependent variables are the amount of rusting and color of the water.
Sounds with small amount of energy______distances than sounds with more energy
A.Shorter
B. Longer
C.same
D. Medium
at what distance above the surface of the Earth is the acceleration due to Earth gravity 0.95 metre per second
square
To Find :
At what distance above the surface of the Earth is the acceleration due to Earth gravity 0.95 meter per second square.
Solution :
Let, acceleration due to gravity at height h is [tex]g_h[/tex].
[tex]\dfrac{g_h}{g}=\dfrac{R^2}{(R+h)^2}\\\\\dfrac{(R+h)}{R}=\sqrt{\dfrac{9.8}{0.95}}\\\\\dfrac{(R+h)}{R}=3.2\\\\h = 3.2R - R\\\\h = 2.2R\\\\h = 2.2\times 6400 \ km \\\\h = 14080\ km[/tex]
Therefore, the height is 14080 km.
Hence, this is the required solution.
What would happen if a researcher failed to realize a thermometer he or she was using has a Celsius and Fahrenheit scale?
Answer:
To obtain a more accurate read on temperature, the researcher should make sure to measure temperature by Celsius degrees rather than Fahrenheit.
Explanation:
Temperature is a measure of heat intensity. In food science experiments, you should always require an exact description of heat intensity. The most commonly used unit of temperature in the laboratory is the Celsius degree because the Celsius temperature scale is based on the boiling and freezing points of pure water. The difference between the points of boiling and freezing temperatures (at 1 atmosphere of air pressure) is divided into 100 equal units, making a Celsius degree 0.01 of the difference between the boiling and freezing points of water, making it the most accurate method of exact temperature reading. It is important to use the Celsius scale if you have a thermometer that reads Celsius and Fahrenheit.
explain why density is more useful for identifying a substance than either mass or volume
Answer:
Mass and volume are extrinsic properties.
A pail may contain water that is 1 kg in mass and 1 L in volume.
A drop of water may be 1 g in mass and 1 mL in volume.
Both are water, but they have different mass and volumes. Therefore you can't identify whether a substance is water just by measuring its mass and volume.
However, the ratio of the mass to volume (density) can be used to identify substances.
How much heat energy is needed to raise the temperature of 135 g of water (specific heat of water = 4.19 J/g-C) from 15 degrees Celsius to 27 degrees Celsius?
Answer:
Required heat = 6,787.8 j (Approx)
Explanation:
Given:
Mass of water = 135 g = 0.135 g
Specific heat of water = 4.19 J/g-C
Change in temperature = 27 - 15 = 12 degrees Celsius
Find:
Required heat
Computation:
Required heat = mcΔt
Required heat = (135)(4.19)(12)
Required heat = 6,787.8 j (Approx)
There are 110 calories (kicalorie) in one serving of cereal. How many calories is that? (Please help meeee)
Answer:
110 calories
Explanation:
110 calories is already 110 calories XD
PLS GIVE BRAINLIEST
formula equation is more informative than a word equation why
Answer:
yes
Explanation:
this is because the formula equation shows the details on how they solved the equation