Answer:
b) sharpening a pencil
Explanation:
If you melt lead, boil water, or dissolve sugar in water, you can return all of them back to their original state. If you sharpen a pencil, you can't reattach the shavings as they were originally.
You may put all of them back to their original states by melting lead, heating water to a boil, or dissolving sugar in water. You cannot rejoin the shavings from a sharpened pencil in their original position. Thus, option B is correct.
What is irreversible physical change?When something changes physically but not chemically, it has undergone an irreversible physical alteration that cannot be reversed.
Sharpening a pencil is a perfect example of an irreversible physical change. The wood turns to dust when you sharpen it. Just in a different shape, it is still wood. That wood dust cannot be transformed back into a pencil.
You cannot put a piece of paper back together the same way it was before you tore it if you tear it into tiny pieces.
An irreversible alteration is one that cannot be undone or that cannot be returned to its original state, such as when milk turns into curd, iron turns rusty, paper burns, food is cooked, etc.
Therefore, sharpening a pencil is an irreversible physical change
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oxidation is a example of ?the answer choices are are here
A.a financial property,B.a chemical property,C.cool science stuff,D.a physical property
Answer:
B. a chemical property
Explanation:
Oxidation requires a chemical reaction to occur, therefore it is a chemical property.
A brief explanation to this question: "Why are neon signs/fireworks different colors? Please help me. Do not look up internet
Answer:
when lit, the atoms of different chemical compounds inside the firework absorb energy, when the electrons fall back to lower energy levels, they give off colored light. Depending upon the chemical used, different colors are produced. neon lights or signs are glass tubes filled with neon gas. When the light is plugged in, the electrical energy causes the electrons of neon to jump to higher energy levels, when they go to lower levels, colored light is given off. The neat thing is that the neon never gets used up. The only thing that gets used up is the electricity. The electrons don't get destroyed and can be used over and over again jumping levels. Neon glows with an orange light, but you know that neon signs can be lots of different colors. The variations come when different gases other than neon are used such as argon, or krypton or when the tube is painted so that with the light produced it produces a certain color.
Explanation:
After being excited by high levels of electrical energy (as in neon signs) or heat energy, various elements and molecules will emit their own specific colors of light.
What are basis behind fireworks?Metals burn in a variety of colors. When a copper compound is lit, for example, the flame is blue-green.
Calcium burns red, while potassium burns purple. Metals are combined to produce various colors in fireworks.
The appearance of each firework is determined by the type of stars it contains, as well as the size and quantity of these pellets.
Some stars contain metal salts, which produce brilliant colors, while others contain a variety of chemical compounds that produce dazzling light effects such as strobing, sparkling, and others.
Various elements and molecules will emit their own specific colors of light after being excited by high levels of electrical energy (as in neon signs) or heat energy (as in the fireworks).
Thus, the neon signs or fireworks provide different colors.
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hello nice ppl(ɔ◔‿◔)ɔ ♥
Answer:
Hi
Explanation:
How has your brainly experience been so far? Are you liking?
Answer:
Thx you are sooo noice
Explanation:
UwU U3U
Determine how you would prepare 220 mL of a 0.500 M potassium hydroxide solution starting with: a) solid potassium hydroxide b) a 1.25 M potassium hydroxide solution
Answer:
a) 6.17 g of solid KOH
b) 88.0 mL of a 1.25 M potassium hydroxide solution
Explanation:
a) We have to determine the mass of solid potassium hydroxide that has to be weighed to prepare 220 mL of a 0.500 M potassium hydroxide solution. We will also require the molar mass of potassium hydroxide, KOH, 56.11 g/mol.
0.220 L × (0.500 mol/L) × (56.11 g/mol) = 6.17 g
b) We will use the dilution rule to determine the volume of the 1.25 M potassium hydroxide solution to be measured.
C₁ × V₁ = C₂ × V₂
V₁ = C₂ × V₂ / C₁
V₁ = 0.500 M × 220 mL / 1.25 M = 88.0 mL
What is the role for dna in determining an organisms traits?
Answer:
DNA contains the genes or the genetic material of an organism. Its role is to store information that are essential in controlling the genetic makeup or producing a certain characteristic of an organism.
How is the nuclear structure of an atom similar to the non-nuclear structure?
Answer:
It has shells of protons and neutrons.
Explanation:
The nuclear structure of an atom is similar to the non-nuclear structure because has shells of protons and neutrons.
What is an atom?An atom consists of a central nucleus that is usually surrounded by one or more electrons.
The total number of neutrons plus protons in the same both before and after the nuclear process, although the total number of protons and the total number of neutrons may be different before and after.
Hence, the nuclear structure of an atom is similar to the non-nuclear structure because has shells of protons and neutrons.
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11. How many moles are in 7.14 X 10 35
molecules of 02?
Answer:
The answer is 1.186 × 10¹² molesExplanation:
To find the number of moles in a substance given it's number of entities we use the formula
[tex]n = \frac{N}{L} \\[/tex]
where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
From the question
N = 7.14 × 10^35 molecules of O2
We have
[tex]n = \frac{7.14 \times {10}^{35} }{6.02 \times {10}^{23} } \\ [/tex]
We have the final answer as
1.186 × 10¹² molesHope this helps you
Does changing the number of neutrons affect the atomic number?
Answer:
awsdxcvawsd
Explanation:
Answer:If you change the number of neutrons in an atom, you get an isotope of the same element. The addition of a neutron can make an atom radioactive. When you change the number of protons in an atom, you will change the atom from one element to a different element.
Explanation:
please help me.......
Answer:
D as in :D lol
example of physical property
Answer:
Color. I thinkkk.
Phyiscal properties are defined as properties that can be measured or observed without changing the chemical nature of the substance.
Some examples of phsyical properties are:
- Color
- Density
- Volume
- Mass
- Boiling or Melting Points
HELP PLEASEE
Name three elements present in the ingredients of the cereal drink which are not listed in the nutrition facts
Answer:
Let's start with the fact that cereals , are made of grains and are mostly carbohydrates. therefore they contain carbon oxygen and hydrogen. They also contain proteins so have nitrogen. Plants have the minerals that are in the soil where they grow, so the list you have is correct. They also generally have added vitamins ad minerals. The vitamins contain C, H, O N, and a few others such as sulfur, The added minerals might contain:copper, iron, zinc, cobalt, selenium, silicon and molybdenum .
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The three elements present in the ingredients of the cereal drink which are not listed in the nutrition facts are Iron, Calcium, and Zinc
Cereals are monocotyledonous grass crops cultivated annually for the purpose of consumption. They are rich in fiber and energy. Examples of them include;
maize, barley, wheat, oat, rye, etc.Cereal drinks are processed drinks extracted from cereal crops through fermentation. They are rich in nutrients as they contain important sources of carbohydrates, dietary protein, and vitamins.
The ingredients present in a cereal drink are composed of essential elements such as:
copper, cobalt, iron, zinc, molybdenum, iodine, chromium, and selenium.Some of which are not listed in the nutrition facts are Iron, Calcium, and Zinc.
Therefore, we can conclude that the elements present in the ingredients of the cereal drink which are not listed in the nutrition facts can be Iron, Calcium, and Zinc.
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How much heat is required to melt 42.0 grams of water at 0*C?
Hurry...
Answer:
Heat required to melt 42 g if ice is 13,860 J
Explanation:
The amount of heat required to melt grams of water at 0°C is given as follows;
The mass of the ice (water), m = 42 g
The latent heat of fusion of ice Δ[tex]H_f[/tex]= 330 J/g
Therefore, heat required to melt 42 grams is given as follows;
Heat required to melt ice = Mass of the ice, m × The specific latent heat of fusion of the ice, Δ[tex]H_f[/tex]
Heat required to melt 42 g if ice = m × Δ[tex]H_f[/tex] = 42 g × 330 J/g = 13,860 J
Heat required to melt 42 g if ice = 13,860 J.
In a sample of 400 lithium atoms, it is found that 30 atoms are lithium-6 (6.015 amu) and
370 atoms are lithium-7 (7.016 amu). What is the average atomic mass?
Answer:
667.3
Explanation:
Phenolphthalein turns litmus paper what color?
Litmus paper and Phenolphthalein are both indicators. This means they will change colour in the presence of an acid or a base.
Litmus paper turns blue in a base and remains red when it is in contact with an acid or neutral solution. Phenolphthalein turns pink in a base, but is coluorless in an acid or neutral solution.
Jakasia needed to find the volume of a plastic container in L to see if the 170 L of
solution that she had would fit inside. She knew that one side was 2.5 ft, the
height of the box was 60 cm, and width of the box was 0.8 m. Use dimensional
analysis to determine if Jakasia's solution will fit in the container.
Answer:
The solution will fit into the container.
Explanation:
The following data were obtained from the question'
Volume of solution = 170 L
Length of container (L) = 2.5 ft
Height of container (H) = 60 cm
Width of container (W) = 0.8 m
Volume of container (V) =?
Next, we shall express the length, height and breadth I the same unit of measurement. In this case, we shall all in centimetres (cm).
For the length:
1 ft = 30.48 cm
Therefore,
2.5 ft = 2.5 ft × 30.48 cm / 1 ft
2.5 ft = 76.2 cm
Thus the length is 76.2 cm
For the width:
1 m = 100 cm
Therefore,
0.8 m = 0.8 m × 100 cm / 1 m
0.8 m = 80 cm
Thus, the width of the container is 80 cm.
Next, we shall determine the volume of the container as follow:
ength of container (L) = 76. 2 cm
Height of container (H) = 60 cm
Width of container (W) = 80 cm
Volume of container (V) =?
Volume = length × width × height
Volume = 76.2 × 80 × 60
Volume = 365760 cm³
Finally, we shall convert 365760 cm³ to litre (L). This can be obtained as follow:
1000 cm³ = 1 L
Therefore,
365760 cm³ = 365760 cm³ × 1 L/ 1000 cm³
365760 cm³ = 365.76 L
Therefore, the volume of the container is 365.76 L
Since the volume of the container (i.e 365.76 L) is bigger than the volume of the solution (i.e 170 L), therefore, the solution will fit into the container.
Analyzing a blood sample usually involves which type of separation method?
screening
distillation
centrifugation
filtration
Answer:
the answer is b
Explanation:
i just did quizz
how long does it take to find out that you just want to stuff your face in chocolate
Answer:
no to long
Explanation:
thanks for the points
A skittish squirrel is climbing vertically on a tree. Its
motion is shown on the following graph of vertical
position y vs. time t.
6
5+
3
2+
1
→t(s)
2
3
4
5
6
7
8
9
What is the instantaneous speed of the squirrel at time
t=2 s?
Answer: 1
Explanation:
Answer:
-0.1
Explanation:
how do i know if they are congruent
Which of the following is the least likely to remain homogeneous?
. O A. All of these
O B. A supersaturated solution
O C. An unsaturated solution
O D. A saturated solution
Answer:
all
of them
Explanation:
Sciences Grad Bosch Law of Conservation of Mass - Assess it
contents
Target: 10/2001
Science and Enging
Achemical reaction takes place in a closed system. The mass of the reactants before the reaction was
55 watte mass of the products of the reaction be according to the law of conservation
Properties of Matter
Answer:
55
Explanation:
According to the law of conservation properties of Matter in a closed system the mass of reactants is equal to the mass of products. Because there is no lose of matter or energy in closed system
There are seven petals on that flower.
O
qualitative
quantitative
In the apple activity you completed which of the following is an example of a constant
Answer: the type of apple because it is an example of a constant
Explanation:
(True or False) Only an odd number of orbitals is possible for any electron sublevel?
Answer:
The statement is true
I found this doing research.
Apparantly, each sub level is made up of one or more orbitals and the orbitals in each sub level are always odd number. Each orbital can only have two electrons and those two electrons will have opposite spin.
Explanation:
Answer:
True
Explanation:
The number of shovels and cost per 1000 kg for
Ca(OH)2
Answer:500
Explanation:
Please help me with this I’ve been on this question for 10 minutes now...
Answer:
A
Explanation:
we know that pangea was when all the continents were connected and the tectonic plates moved, causing pangea to split into multiple pieces. so north america was formed by moving tectonic plates.
i hope this helps :))
define atom and give an example
Answer:
Many atoms consist of a positively charged nucleus composed of protons and neutrons surrounded by a negatively charged cloud of electrons. At its most basic level, an atom is any particle of matter that contains at least one proton. ... Here are some examples of atoms: Neon (Ne) Hydrogen (H)
Explanation:
10.0 J of energy is required to increase the temperature of 1 g of water by 10oC. What is this value in calories? In kcal?
10 J = 2.39 cal = 2.39 x 10⁻³ kcal
Further explanationThe joule is one unit of energy. energy itself can be expressed in units such as calories, BTU, kg⋅m²s⁻²
An example of energy calculation is the calculation of heat in heat transfer
Heat can be calculated using the formula:
Q = mc∆T
Q = heat, J
m = mass, g
c = specific heat, joules / g ° C
∆T = temperature difference, ° C / K
10 J if we convert into calories and kcal
[tex]\tt 1~J= 0.239~cal\\\\10~J=2.39~cal\\\\2.39~cal=2.39\times 10^{-3}~kcal[/tex]
Line M passes through the points (-5, 9) and (-1,9).
12
10-
8
6
2
-12-10-8-6-4-22
2
6 8 10 12 X
6
-10
-12-
Which is true of line M?
Answer:
line m is vertical line with an undefined slopel line correct answer is 6 8 10 12 x
Quais são os três tipos de tecidos musculares? E)celulas,estriado esqueletico, estriado liso. B)esttiadi esqueletico, liso, estriado cardiaco c)estriado liso, estriado esqueletico, estriado cardíaco. D)liso, celulas, esteiado cardíaco. ESSA PERGUNTA E DE CIENCIAS MAS NAO TEM VIENCIAS ALI PRA ESCOLHER;-;.
Answer:
c)estriado liso, estriado esqueletico, estriado cardíac
Explanation:
Los 3 tipos de tejido muscular filho cardíaco, liso y esquelético.
O músculo esquelético é responsável pelo movimento dos tons e das outras estruturas. La contracción del músculo cardíaco permite que o corazón bombee sangre. Los músculos lisos permitem que os alimentos se muevan a través del tracto digestivo y también ayudan al cuerpo a absorvedor los nutrientes.