If you place a glass rod over the burning candle, the glass turns black. The happening in the following substances are:
a. the wax is a both.
b. the wick is neither
c. the glass rod is a physical change.
What are chemical and physical reactions?Chemical reactions are those in which the substance changes its composition and totally transformed into a new substance. A chemical reaction involves reactants ad products.
Physical changes are temporary or permanent. Due to changes in the temperature or environment, some matter changes its shape and size.
Thus, the reactions are:
a. the wax is a both; Physical change-solid to liquid. Chemical change-burned to CO2 + H20 + heat + carbon as seen as black on the rod.
b. the wick is neither; the wick does not change, just provides a conduit for the wax to flame
c. the glass rod is a physical change; the carbon is only deported.
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A teacher is instructing students about the states of matter. He wants to compare the
numbers of elements that exist as solids, gases, and liquids at room temperature.
Which kind of illustration should the teacher use to present this information?
The teacher can present this information using a bar chart.
In science, charts are commonly used to present information where comparison is necessary.
Bar charts are especially useful when we intend to show large changes.
In the periodic table, elements exists in various states of matter;
SolidLiquidGasSometimes, as a teacher, you may need to compare the number of elements that exist as solids, gases, and liquids at room temperature.
This comparison is easily brought out using a bar chart since the changes involve large numbers.
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True or false?
1. Cells carry on the processes that keep organism live?
True or false?
2. The digestive system is in the levels of organization under organ?
Write 0.034 in scientific notation.
Answer:
0.034 = 34×10^-3
Explanation:
This is because the special point is notated until it goes in front of the first counting number
Scientific notation is a way of expressing numbers that are very large or very small in a compact and standardized format. 0.034 in scientifc notation is written as 3.4 × 10⁻³
In scientific notation, a number is expressed as the product of a coefficient and a power of 10. The coefficient is a decimal number greater than or equal to 1 but less than 10, and the power of 10 represents the magnitude of the number. The power of 10 indicates the number of places the decimal point must be moved to obtain the original number.
For example:
The number 4,500,000 can be written in scientific notation as 4.5 x 10⁶, where the coefficient is 4.5 and the power of 10 is 6.
The number 0.000043 can be written in scientific notation as 4.3 x 10⁻⁵, where the coefficient is 4.3 and the power of 10 is -5.
Scientific notation allows for easy representation of very large or small numbers and simplifies calculations involving these numbers. It is particularly useful in scientific fields where values such as distances, masses, and concentrations can vary over a wide range.
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the process by which charged plasma particles
revert back to a gas
Answer:
Plasma, in physics, an electrically conducting medium in which there are roughly equal numbers of positively and negatively charged particles, produced when the atoms in a gas become ionized. It is sometimes referred to as the fourth state of matter, distinct from the solid, liquid, and gaseous states.
Each of the following can be used to make observations, except: *
A calculator
A digital scale
Your sense of smell
A microscope
Answer:
Calculator
Explanation:
A calculator is used to make, well calculations
You can use a scale to get information about the weight of an object, and you can observe how weight changes in relation to size etc.
For obvious reasons, you can observe different scents
Again a microscope is an observational tool
A ___________
is a process that occurs when
one or more substances are changed into one or more new
substances. For example, when zinc and sulfur are mixed
together with the addition of energy in the form of heat, zinc
sulfide (ZnS) is produced.
Answer:
Reaction??
Explanation:
Which of these could be a measurement of an object’s mass?
a. 24 newtons
b. 24 grams per milliliter
c. 24 meters
d. 24 grams
Answer:
Mass is a measure of the amount of matter in a substance or an object. The basic SI unit for mass is the kilogram (kg), but smaller masses may be measured in grams (g). To measure mass, you would use a balance.
does nail polish remover sink or float
nail polish remover float
Answer:
it will float on water
explanation:
Geekette hypothesized that since it floated on the water, like ice does, it must be less dense. ... According to Ken Johnsen, who lists his expertise in chemistry, the components of nail polish indeed make it less dense than water
Which of the following diagrams shows a pure substance that is composed of only individual atoms and not molecules?
Answer:
Ar
Explanation:
the last one
The diagram that shows a pure substance which is composed of only individual atoms and not molecules will be: argon gas. Option D is correct.
A pure substance composed of only individual atoms is called an element. In the periodic table, each element is represented by a unique symbol, and its atoms cannot be further broken down into simpler substances by chemical means.
Liquid water: Water (H₂O) is a compound composed of two hydrogen atoms bonded to one oxygen atom. It consists of molecules, not individual atoms.
Hydrogen gas: Hydrogen gas (H₂) is composed of two hydrogen atoms bonded together to form a diatomic molecule. It is not composed of individual atoms.
Carbon dioxide GAS: Carbon dioxide (CO₂) is a compound consisting of one carbon atom bonded to two oxygen atoms, forming a molecule of CO₂.
Argon gas: Argon (Ar) is an element, and in its pure form as a gas, it exists as individual argon atoms (Ar). It is not bonded to any other atoms, and there are no molecules involved. Therefore, argon gas is composed of individual atoms and represents a pure substance.
Hence, D. is the correct option.
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A 2.00 mL sample of a substance A has a density of 18.4 g/mL and a 5.00 mL sample of
substance B has a density of 35.5 g/mL. Do you have an equal mass of substances A and
B? Explain your answer.
Answer: No, the samples are not of equal masses.
Explanation: Mass is volume X density
A: (2ml)*(18.4g/ml) = 36.8 g
B: (5ml(*(35.5g/ml) = 177.5 g
Define the following terms:
-hypothesis:
- theroy:
-law:
Answer:
hypothesis = A tentative explanation for a question, testable through experiments.
theory = An explanation supported by many experiments, answers "why".
law = A relationship in nature supported by many experiments.
Explanation:
PLS HELP ME
The moon is 2.39 • 10^5 miles from the earth. The
average man is 6 feet tall. How many men would have
to stand on top of one another to reach from the earth
to the moon? (there are 5,280 feet in a mile. How many
miles is 6 feet?)
Number of men required to stand on top of each other to reach moon from earth are :
[tex] \boxed{ \boxed{ \: \: \: \: \: \: \: 210320000 \: \: \: \: \: \: \: }}[/tex]
negative
in your own words, why dose a car have
accelerction when it stops at a stop light?
Answer:
since it has lower mass. the force acting on it results in larger acceleration.
Jerod used a golf club to hit a ball what was the action and reaction
Answer: I'm pretty sure the action is Jerod swinging the golf club and the reaction is hitting the ball
Explanation:
Employers may not fire or other wise discriminate against an employee who does which of the following
Answer:
race, religion, sex, if they are 40 or older, have a disability, pregnancy/childbirth. hope that helped
Why is agar medium used in Petri dishes?
A.It makes bacteria appear larger.
B.It sterilizes the petri dish.
C.It helps microorganisms grow.
D.It makes cells glow.
Answer:
C is the correct answer.
Explanation:
Agar provides a solid growth surface for the bacteria, upon which bacteria reproduce until the distinctive lumps of cells.
The agar medium is used in Petri dishes because it helps microorganisms grow. option C is correct.
What is a microorganism?A microorganism is a microscopic body that cannot be seen with the normal human eyes on anything it can be a virus or bacteria or both. Viruses are disease-causing mostly but there are some good bacteria too.
The use of agar medium is the source of food for the microorganism as all the micronutrients and macronutrients with essential amino acids are present into it.
Therefore, option C is the correct agar medium used in Petri dishes because it helps microorganisms grow.
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The volume of a brick is 52 cubic inches. Which choice best describes its volume?
Answer:
I think he was right but not explaining
Explanation:
I think it is C cause.... the volume of a material is the amount of matter that matterial can hold. it should the the amount of space the whole material takes up.
so C is the answer.
pls make this the brainliest.
not because it is, but because I asked.
_______ is an example for isotone. a)argon and carbon b) uranium and carbon c) carbon and boron d)sulphur and boron.
Isotones are nuclides that have the same neutron number but a different proton number. Therefore the answer is C. boron and carbon.
Answer:
c) carbon and boron
Explanation:
They have the same number of neutrons but different number of protons.
They both contain 7 neutrons
You are given 2 balls that are made of the same material. They are also the same size and color. One is hollow and one is solid. Determine the physical property that could be used to identify the ball as a solid.
Group of answer choices
boiling point
solubility
pH
density
Answer:density
Explanation:
it’s how’s how dens the ball is
an object is traveleing at a speed of 7.500.0 cm/sec. what is this value in km/day
Answer:
1 cm » 0.00001 km
1 sec » 1/86400 days
[tex]7500 {cm \: sec}^{ - 1} = \frac{75 00\: cm}{1 \: sec} \\ \\ = \frac{7500 \times 0.00001 \: km}{(1 \times \frac{1}{86400}) \: day } \\ \\ = { \boxed{ \boxed{6480 \: km \: {day}^{ - 1} }}}[/tex]
How to separate thumb tacks and plastic beads?
How to separate color components of a leaf?
Explanation:
Add ethanol ( or whichever you choose) into the mixture.
Use a filter to separate the salt from mix.
Evaporate the ethanol/petroleum spirit -sugar mix to get the sugar by itself.
Done!
Answer: 1) a) Use a magnet, or b) add to water abd scoop off the floating plastic beads
2) Grind the leaf and solubilize what you can in water, then use filter paper as a chromatograph to separate the colors.
Explanation:
1) Look for any property between the two substances that has a large enough difference to provide an avenue for separation. Density is good, particle size also can be used, solubility, and magnetic properties, among others.
2) https://www.britannica.com/science/paper-chromatography
Write the reaction to prepare C2H5Br from (image attached)
a) alcohol using PX3
b) Alcohol using HX
The equations for the preparation of C₂H₅Br from alcohol using PX₃ and HX are shown in the attachment below.
a) Preparation of C₂H₅Br from alcohol using PX₃
In PX₃, X refers to the halides (F, Cl, Br etc.). Since the desired ethyl halide is ethyl bromide (C₂H₅Br) , then X in PX₃ will be Br. Therefore, PBr₃ will be used in the reaction as shown in the attachment below.
b) Preparation of C₂H₅Br from alcohol using HX
Also, In HX, X refers to the halides (F, Cl, Br etc.). Since the desired ethyl halide is ethyl bromide (C₂H₅Br), then X in HX will be Br. Therefore, HBr will be used in the reaction as shown in the attachment below.
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Need help please
Which of the following physical changes shows a change in a substance’s state of matter?
A. A piece of paper being torn in half
B. Clay being molded into a bowl
C. An ice cube being crushed
D. Liquid water becoming steam
Answer:
c
Explanation:
because when you crush an ice it would break into peace's and the ice would not be a solid
Scientists test their ideas about things they cannot observe directly by building
Answer:
yes
Explanation:
Testing scientific ideas
Testing Ideas. Testing hypotheses and theories is at the core of the process of science. ... match actual results observation, that lends support.
A car travels 4 miles in 0.08 hours. The speed of the car is miles/hr.
Please help me, I really need it, God Bless you <3
#1
[tex]\\ \sf\longmapsto {}^{88}_{38}Sr^{2+}[/tex]
As 2 electrons are donated Hence the No of electrons =38-2=36#2
[tex]\\ \sf\longmapsto {}^{51}_{23}V^{3+}[/tex]
As 3 electrons donated the no of electrons=23-3=20#3
[tex]\\ \sf\longmapsto {}^{55}_{26}Fe^{3+}[/tex]
No of neutrons=55-26=29#4
[tex]\\ \sf\longmapsto {}^{112}_{48}[/tex]
As 2 electrons are donated no of electrons =48-2=46#5
[tex]\\ \sf\longmapsto {}^{210}_{82}Pb^{2+}[/tex]
No of neutrons=210-82=128Calculate the mass of a solid metal cylinder with a density of 2.6 g/cm", a
diameter of 1.8 cm, and a length of 4 cm.
Answer:
V= π ×r² × h
V = 3.14 × (0.9)² × 4
V = 3.14 × 0.81 × 4
V = 10.1736
Mass = Volume × density
M = 10.1736 × 2.6
M = 26.45136 g
Why type of data must be plotted on a graph for the slope of the line to represent density?
Answer:
you need data that has at least one independent variable in order to plot a graph for a slope of the line
Explanation:
