Answer:
B
Explanation:
a chemical change is something that can not be reversed, so you may think crushing a rock but it isn't because crushing a rock is a phisical change not chemical and if you freeze water you can melt it and of you melt ice you can freeze it, so those can be reversed. So the answer is B because that can not be reversed
Since new substances are formed in chemical changes, Lighting a Match is a chemical change., option B.
What is a chemical change?A chemical change refers to a change which is not easily reversible and in which new substances are formed.
In chemical changes, large amounts of heat is involved and changes in the mass of the original substance may occur.
Examples of chemical changes are combustion of substances, oxidation of substances, etc.
From the given options, the change which involves great heat changes and in which new sure are formed is Lighting a match.
Therefore, Lighting a match describes a chemical change, option B.
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The density of silver is 10.5 g/cm3. What is the volume of the silver if it has a mas of 38.4 g
Answer:
The answer is 3.66 mLExplanation:
The volume of a substance when given the density and mass can be found by using the formula
[tex]volume = \frac{mass}{density} \\[/tex]
From the question
mass = 38.4 g
density = 10.5 g/cm³
We have
[tex]volume = \frac{38.4}{10.5} \\ = 3.6571428...[/tex]
We have the final answer as
3.66 mLHope this helps you
how many ML is this ?
Answer:
It's right below 620. So id say 618 ML
Explanation:
Which of the following elements typically attract 1 electron to its valence shell?
Answer:
Hydrogen lithium and sodium
What happens to the number pf protons in an atom as you move across a period.
The number of protons increase
The number of protons stay the same The number of protons decrease
Answer:
A. The number of protons increase.
Explanation:
Each element rank is determined by the number of protons.
Hydrogen is #1 with 1 proton, Helium is #2 with 2 protons, Lithium is #3 with 3 protons, and so on.
what happens to the speed and acceleration when you let go
Answer:
the speed will increase and so will the acceleration. then after a bit the acceleration will decrease due to air resistance until there is no acceleration. Then the speed will continue to decrease when there is no acceleration anymore.
What is a key property of crystals?
Answer: Crystals differ in physical properties, i.e., in hardness, cleavage, optical properties, heat conductivity, and electrical conductivity.
These properties are important since they sometimes determine the use to which the crystals are put in industry.
hope this helps :)
Answer:
A crystals key properties are hardness, cleavage, optical properties, heat conductivity, and electrical conductivity.
Explanation:
These properties are important since they sometimes determine the use to which the crystals are put in industry.
What are 4 things an element can do with electrons
Answer:Each shell can hold a maximum number of electrons. moving through the elements in the periodic table, each atom has one more electron than the last because the number of electrons is the same as the atomic number. Electrons occupy the shells in order, starting with the shell that is nearest the nucleus.
Explanation:
Ca(ClO4)2
Ionic compound name
Answer:
I thing Calcium Perchlorate
A model stands on a scale and finds her weight to be 105 pounds. If
the pressure exerted by her feet on the scale is 2.16 pounds per
square inch, what is the area of her feet in cubic centimeters?
__cm2
The area = 313.612 cm²
Further explanationForce (F) can cause objects to move
While pressure (P)is the force per unit area
[tex]\tt P=\dfrac{F}{A}[/tex]
weight=force=105 pounds(lb)⇒english units
pressure = 2.16 lb/in²
Thea are (A)
[tex]\tt A=\dfrac{F}{P}=\dfrac{105}{2.16}=48.61~in^2\\\\1~in^2=6,4516~cm^2\\\\48.61~in^2=313,612~cm^2[/tex]
Predict: If the skater starts at a height of 2m on one side of the ramp and starts to move, how high will he get on the other side? Explain
Answer:
Sliding friction
Explanation:
SLiding friction produces force
Below is a bar graph on candy allowance compared to the child's happiness.
What is the dependent variable of this experiment?
A) average level of happiness
B) how often do you eat candy
C) type of candy
D) if candy is given as a reward
Answer:
There is no bar graph attached to this question, however, the question can be answered based on the information given in the question.
The answer is A) average level of happiness
Explanation:
In an experiment, the dependent variable is the variable which is measured by the experimenter. It is the variable that responds to changes made to another variable called independent variable.
In the case of this question, it can be determined, even without the bar graph, that the experiment entails how candy allowance affects a child's happiness. Hence, the candy allowance is changed to influence or cause a response in the child's happiness, which is then measured. Therefore, the AVERAGE LEVEL OF HAPPINESS is the dependent variable.
The diagram shows a model of an atom. The model has four different symbols on it. Each symbol represents a
different role for one of the particles within the atom.
Model Atom
w
In this model, which particle determines the reactivity of this atom?
A W
ОВ. Х
O C. Y
O D. Z
The Answer is particle Z
Answer:
The model is particle W
Explanation:
how did the ancient greek understanding of atomic particles likley influence dalton research?
Answer:
The Greeks called these particles atomos, meaning indivisible, and the modern word “atom” is derived from this term. Democritus proposed that different types and combinations of these particles were responsible for the various forms of matter.
Explanation:
hope it helps
The idea of indivisibility of the atom upheld by Dalton was largely derived from early Greek philosophers.
John Dalton was the first scientist to begin an empirical study of atomic theory. Before this time, all that was known about the atom were largely based on the speculation of Greek philosophers.
However, one recurring theme among Greek philosophers is that atoms are indivisible. This idea that atoms are indivisible became a very strong pivot of the Dalton's theory of the atom.
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THIS IS URGENTTT!!
can someone summarise the speed of sound for me? :) I'm not rly good at science ahah, anyone good at it.?
increasing temperature:
causes particles to ....?
which means that sound will travel...?
making something more solid:
causes particles to ....?
which means that sound will travel...?
Explanation:
The speed of sound is the distance that sound waves travel in a given amount of time. ... Generally, sound waves travel most quickly through solids, followed by liquids, and then by gases. For a given medium, sound waves travel more slowly at lower temperatures.
Answer:
increasing the temperature will also increase the number of collisions between molecules per unit time. Which means molecules at higher temperatures have more energy, thus they can vibrate faster. Since the molecules vibrate faster, sound waves can travel more quickly.
Slow down, but generally not move from there place. Which means molecules at a lower temperature have less energy, meaning sound waves can't travel through in a solid.
Explanation:
Sound waves can only travel in space if there are enough particles around to transmit the energy in the wave from the source thus meaning more kinetic energy more sound waves being able to quickly get through
Mark Me Brainliest.
What mass of calcium bromide is needed to prepare 150.0 mL of a 3.50 M solution? (Assume that the molecular weight of CaBr2 is 200.618 g/mol)
Answer:
105g
Use the following formula to calculate the mass of calcium bromide that is needed:
volume of solution × molar concentration × molar mass = mass of solute
The result is 105 g, which has three significant figures, because the term with the least precision (3.50 M) has three significant figures.
Explanation:
One of your test tubes falls over and breaks during a lab. Describe how you would handle this situation?
Answer:
You would inform your teacher but don't take any safety equipment off
Explanation:
don't try to clean it yourself, tell a teacher immediately
(i put it in the wrong section)
Plz help!
What is 1 item that is a compound?
Give an example of how the 1 item is a compound
Answer:
EX: Table Salt (NaCl)
Explanation:
A compound is a substance that has two or more elements whos atoms are bonded together.
A baseball player hits a ball towards the outfield. *
Newton's 1st Law
Newton's 2nd Law
Newton's 3 Law
Law of Universal Gravitation
Law of Conservation of Momentum
Answer:Newton's 2nd law
Explanation:
Answer: newtons 2nd law
Explanation:
I need help with this before 11:15 please.
For 1 it is balanced for both Net Horizontal force and net vertical force.
For 2 Vertical is balanced and horizontal is unbalanced.
For 3 vertical is not horizontal is.
For 5 both are balanced.
for 6 vertical is, horizontal is not.
for 7 vertical is horizontal is not.
for 8 neither are balanced.
Why do we believe that these strange quantum laws are correct? Group of answer choices Experiments show they're sometimes right. There haven't been any experiments done on them because they can't be tested, so we just think they're right. In experiment after experiment, they're always right. We actually don't believe they're right, we just like to talk about them.
Answer:
In experiment after experiment, they're always right
Explanation:
In science, nothing is accepted unless it can be supported by empirical evidence, this includes the quantum laws.
A plethora of experiments have confirmed these quantum laws to be correct and reliable.
Hence, all the quantum laws are backed up by plenty scientific evidence that show that the laws are indeed correct.
The weight of a medium sized apple is about _____. A) 1N B) 2N C) 1kg D) 2kg
Answer:
1n
Explanation:
which two elements on the periodic table are in the same period?
Answer:
Platinum and Gold ig.
HURRRYYYY!!!!!! A nonmetal in the same group as Pb
Answer:
carbon C
Explanation:
Which activity uses water for both recreational and industrial purposes?
machinery cooling
waterskiing
irrigation
fishing
Answer:
D. Fishing.
Explanation:
Fishing refers to an activity which typically involves catching fishes for both recreational (sports or hobby) and industrial (feeding or sales) purposes. In finishing, the fishes are caught from water such as a pool, lake, river etc. through the use of fishing nets, rod and lines and fish hooks.
Basically, when fishing is done with family members, peers or even individually such as on a vacation, sports competition and pleasure, it is mainly considered to be for recreational purposes.
However, when fishing is done on a commercial basis such as selling them consumers, it is considered to be for industrial purposes.
Hence, fishing is an activity which uses water for both recreational and industrial purposes.
Answer:
It's d fishing
Explanation:
got it correct on edge
hi i need help. Select all the statements that are true.
a
Cells come in different sizes and shapes.
b
All organisms are made of many cells.
c
Some organisms are made of just one cell.
d
All cells are the same size and shape.
e
Most cells are too small to see with the naked eye.
Answer:
A, C, E
Explanation:
hope this helps
The true statements are - Cells come in different sizes and shapes, some organisms are made of just one cell and most cells are too small to see with the eye. Thus, the correct options are options A, C and E.
Cells are the basic structural and functional units of life. They are the smallest entities that can carry out the fundamental processes necessary for an organism's survival.
Cells are enclosed by a cell membrane, which separates the internal components from the external environment. Inside the cell, various parts perform specific functions, such as energy production, protein synthesis, and storage of genetic material.
Cells can be categorized into two broad types: prokaryotic cells, which lack a nucleus and eukaryotic cells, which have a nucleus.
Thus, the ideal selection is option A, C and E.
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Which element in row 6 of the periodic table (shown below) has the largest radius?
Select one:
a. Hg
b. Cs
c. Os
d. Rn
Answer:
Cs
Explanation:
It has less amount of proton numbers so they won't attract the electrons as much as the other elements with increased number of protons will.
what is an orbital?
Answer:
Relating to orbit or orbits
Explanation:
Which statements describe an aquifer? Select the three correct answers.
layer of permeable rocks
can be created only by digging or drilling
underground water storehouse
layer of impermeable rocks
can be recharged after being depleted
Answer:
-layer of permeable rocks
-underground water storehouse
-layer of impermeable rocks
Explanation:
The statements that describe aquifer are:
A. a layer of permeable rocks.
C. underground water storehouse.
D. the layer of impermeable rocks.
What is an aquifer?Aquifers are bodies of permeable rock or sediment that have been flooded by groundwater.
As rainwater penetrates through the earth, groundwater enters an aquifer.
It has the ability to go through the aquifer and re-emerge via springs and wells.
There are three types of aquifers
ConfinedUnconfinedPerchedThus, the correct options are A. a layer of permeable rocks., C. underground water storehouse., D. the layer of impermeable rocks.
Learn more about aquifer
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When a substance is in the liquid state, how are the particles of that substance
behaving
Answer:
In liquids, particles are quite close together and move with random motion throughout the container. Particles move rapidly in all directions but collide with each other more frequently than in gases due to shorter distances between particles. With an increase in temperature, the particles move faster as they gain kinetic energy, resulting in increased collision rates and an increased rate of diffusion.
Explanation:
In liquids, particles are quite close together and move with random motion throughout the container. Particles move rapidly in all directions but collide with each other more frequently than in gases due to shorter distances between particles. With an increase in temperature, the particles move faster as they gain kinetic energy, resulting in increased collision rates and an increased rate of diffusion.
Many enzymes are inhibited irreversibly by heavy metal ions such as Hg2+ , Cu2+ , or Ag+ , which can react with essential sulfhydryl groups to form mercaptides. Enz−SH+Ag+⟶Enz−S−Ag+H+ The affinity of Ag+ for sulfhydryl groups is so great that Ag+ can be used to titrate −SH groups quantitatively. To 10.0 mL of a solution containing 3.4 mg/mL of a pure enzyme, an investigator added just enough AgNO3 to completely inactivate the enzyme. A total of 0.134 μmol AgNO3 was required. Calculate the minimum molecular weight (????r) of the enzyme.
Answer:
Explanation:
one mole of AgNO₃ reacts to inactivate one mole of enzyme
mg of enzyme in 10 mL = 3.4 x 10 mg = 34 mg .
required AgNO₃ = .134 x 10⁻⁶ mole
.134 x 10⁻⁶ mole AgNO₃ is required for inactivating 34 mg of enzyme
1 mole of AgNO₃ will be required for inactivating 34 / (.134 x 10⁻⁶ ) mg of enzyme
= 253.73 x 10⁶ mg of enzyme
= 253.73 x 10³ g of enzyme
Mol weight of enzyme = 253.73 x 10³ .