Chopping a piece of wood
Physical changes are changes affecting the form of a chemical substance but not it's chemical composition.
Answer:
rusting nail: Rusting would only be a physical change if iron molecules remained pure iron throughout the process. Yeah your correct a physical change is anything seen or felt like changing the temperature of water a chemical change can also be seen also like if a iron nail rusts the nails iron atoms were chemically changed by oxygen.
lighting a match: Breaking a match in two pieces is an example of a physical change. Lighting a match and letting is burn is an example of a chemical change. Chemical reactions cause chemical changes. In a chemical reaction two or more substances, called the reactants, form different substances called products.
burning a piece of paper: Burning of paper is not a physical change. It is chemical change as ash is formed in the process which is new compound and oxides of carbon are also released during the process. By the definition of chemical change, we come to know that during chemical change a new substance must form. These changes are irreversible in nature.
chopping a piece of wood: The chopping of wood is a physical change because as stated previously, any physical change can include cutting, bending, sharpening, etc. When a piece of wood is being cut, it undergoes one of these processes. The chopping of wood doesn't alter the chemical structure of the actual wood.
So Its chopping piece of wood!
Hope this helps!!Why can two water molecules stick to each other?
Please help ASAP I’ll make you u as brainlister please 100 points pelaseee
Answer:
(C) im pretty sure is the answer
Explanation:
Answer:
C
Explanation:
PLZ HELP ME. This is my second time posting my question because the first time a person put a random answer. If you do not know the question please do not answer it and leave it to someone else. Thank you, and my question is on the attached image below
Answer: I can not see the image.
PLZ HELP ME. This is my second time posting my question because the first time a person put a random answer. If you do not know the question please do not answer it and leave it to someone else. Thank you, and my question is on the attached image below. Thanks!
Select the correct answer.
In which situation is no work considered to be done by a force?
A.
when the angle between the force and displacement is 180°
B.
when the angle between the force and displacement is 90°
C.
when the angle between the force and displacement is 45°
D.
when the angle between the force and displacement is 0°
Answer:
Explanation:
when the angle between the force and displacement is 0
(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:
1. True or False? The scientific method is defined as a method of research
in which a problem is identified, data is gathered, and a hypothesis is
created based off the data, then the hypothesis is tested.
Answer:
true
Explanation:
please mark BRAINLIEST
HELP ME PLEASE
THANK YOU
Answer:
i think its letter D
Explanation:
Answer:
I think it is B if it is not then I am sorry.
Explanation:
PLEASE HELP ASAP
Please help!!
Answer:
Unwashed hands: This sample swab will have the most bacteria growth, as the bacteria has not been cleaned or Removed at all from this person‘s hands.
Regular Soap: Soap is meant to remove bacteria, not kill it. So by swabbing her hands after washing with regular soap , this technique will not be very effective. This also depends on if the soap is antibacterial or not. By wiping your hand, it may just move the bacteria.
Re-Swabbing: this will have almost the same exact effect as the first experiment. There may be a minute difference between unwashed hands and re-wiping unwashed hands.
Hand sanitizer: hand sanitizer is meant to kill bacteria, not move it, so this should have the least bacteria/virus beings on this swab. Alcohol based hand sanitizer is the most effective, and should kill 99.99 percent of germs. However, you have to wait atleast a minute before swabbing to let hand sanitizer work.
Explanation: I looked it up! :) hopefully this is helpful, please let me know! Have a great day:)
Which two types of information are found in an element's box in the periodic
table?
A. Atomic number
B. Chemical symbol
O C. Chemical formula
O D. Atomic structure
( TWO ANSWERS)
The information we can obtain for an element from periodic table is its atomic number and chemical symbol. Thus option A and B are correct.
What is atomic number?Atomic number of an element is the number of protons of the element. For a neutral atom the number of electrons is equal to the number of protons.
There are 118 elements in the modern periodic table and they are classified into different group and periods. Elements of same number of valence electrons and similar physical and chemical properties are classified into one group.
There are 18 groups and 7 period in the periodic table. Each classification is based on their atomic number. Chemical symbols are used to represent the elements and they can be easily identified by the symbols.
For example, hydrogen have the chemical symbol H and oxygen with O and carbon with C. etc. Similarly we can get mass number of elements from periodic table. Thus option A and B are correct.
To find more about periodic table, refer the link below:
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Sabrina was asked by a classmate why she would place hydrogen in the first column of the periodic table. Which of the following reasons could she give as a response? I. Hydrogen combines with chlorine in the same atomic ratio as sodium. II. Hydrogen is a gas at room temperature. III. Hydrogen forms diatomic molecules.
Answer:
the third option I think
Explanation:
Answer:
3 and 2
Explanation:
i had that question
Why do you elements in the same group have similar properties
Answer:
They have similar properties, because they share similar amounts of electrons in their outer shell, valence electrons! This means they will only be able to interact with other elements with those electrons so they often show similar properties.
Explanation:
hey guys plz plz plz help me I am struggling I am in middle and struggling to answer this plz help
I have never learned how to calculate the specific heat there is a photo if u know plz answer we have a lot of people trying to figure out how to solve this and know one knows so plz if u know give it your best shot.
thank u I will most definitely appreciate it
and if u answer this correctly I will give 50 point and mark brainliest
of u are just trying to get point u rill be reported
so thanks guys.
Answer:
I've already answered this one for you. Anyway, please let me know if you have any more questions or need help!
The momentum of a 23 000 kg truck traveling eastward with a velocity of 50.0 m/s is kom/s
Answer:
Explanation:
I'm not sure what you mean by the units. The answer using kg and ms is 23000 * 50 = 1150000 kg m/s
in the 0 in 0.23 significant
Answer:
No, The Significant Figures are 2 3
Explanation:
Which of these reactants will produce a precipitate if they react?
NaC2H3O2+ HCI
NaOH + HCI
NaNO3 + CaCl2
KOH + Mg(NO3)2
Answer:
KOH+Mg(NO3)2
Explanation:
The double replacement reaction will result in:
2KOH(aq) + Mg(NO3)2[tex]\\[/tex](aq)--> 2KNO3(aq) + Mg(OH)2(s)
Solubility rules prove that Mg+OH^- is insoluble and will result in a precipitate (solid)
Can you explain what vsepr stand for in your own word?
What happens when you touch two hot bowls made of different materials? The wooden and metal bowl are both at the same temperature and HOTTER than your finger. Compare the direction and speed of the heat arrows for the wooden and metal bowl. Explain WHY and what affects HOW the arrows move from the wooden and metal bowl to the finger.
Answer:
Explanation:
Both metal and wooden bowls are at the same temperature . But wood is non-conductor of heat whereas metal is conductor of heat .
If we touch the wooden bowl , heat flows from hot to cold object . Since the finger is at higher temperature , heat flows from finger to wooden bowl . But , since wood is non conducting , it does not allow heat to be conducted through it . Hence very less heat will be conducted from our finger .
On the other hand , if we touch a metal bowl , heat flows from finger to the metal bowl , without any hinderance . Hence rate of heat flow will be fast in case of metal bowl . As a result of it , we feel cool in touching metal bowl . This feeling will be absent in case of wooden bowl.
I need help on Chemistry?
ANYONE PLEASE?
Answer:
1. 1g/ml
Explanation:
1. Density is mass divided by volume (g/mL).
10g/10mL = 1 g/mL
2. When you already know the density and the volume, you can use the density as a unit converter.
[tex]5mL*\frac{20g}{mL} = 100g[/tex]
3. It's the same with density and mass.
[tex]20g*\frac{1mL}{5g} = 4mL[/tex]
A sample of N2H4 has a mass of 25g. Identify the numerical quantity that is needed to convert the number of grams of N2H4 to the number of moles of N2H4. (You do not need to do the actual calculation.)
Answer:
Molecular Mass
Explanation:
It's asking for the numerical quantity. That quantity would be the Molecular Mass. Take the sample mass and divide it by the molecular mass to get the number of moles.
(14g N * 2) + (1g H *4) = 32g / mol of N2H4
To get # of moles, divide the sample mass by the molecular mass
25g / 32g = 0.78125 moles
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 .
Mark me as brainliest if it was helpful
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.
Learn more about essential elements here:
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This chart lists four kinds of polymers and their sources.
A 2-column table titled polymer examples. The first column labeled name of polymer has entries D N A, cellulose, nylon, hair. The second column titled source of polymer has entries inside of cells, plant material, synthetic material, animal material.
What can be known about all four polymers, despite their differences?
They come from living things.
They share ionic carbon bonds.
They are at least 100 monomers long.
They are made of repeating subunits.
Answer:
D. They are made of repeating subunits.
Explanation:
The first column represting polymers such as DNA, cellulose, nylon, hair are labelled with cells, plant material, synthetic material, animal material and They are made of repeating subunits.
Not all the entries in the first column come from living things as nylon comes from synthetic material (man-made). But all four (DNA, cellulose, nylon, hair) are conists of repeating unit.
DNA made up of nucleotides, cellulose is made up of rpeating units of monomer glucose, nylone is made of repeating unit of two monomers hexamethylene diamine and adipic acid, and hair is made of repeating unit of protein called keratin.
Hence, the correct answer is "D. They are made of repeating subunits."
Answer:
They are made of repeating subunits....(D)
Explanation:
hope this helps. also the person above me is correct
truth is everyone is going to hurt you
you just gotta find the one worth suffering for. I love this so much
Answer:
facts
Explanation:
Answer:
yes i understand
Explanation:
? divided by 230 equals 273.1
PLZ HELP I NEED IT
Answer:
Explanation:
X / Y = 230
The answer is infinite. However, below we have created a list of what divided by what equals 230.
230 / 1 = 230
460 / 2 = 230
690 / 3 = 230
920 / 4 = 230
1150 / 5 = 230
1380 / 6 = 230
1610 / 7 = 230
1840 / 8 = 230
2070 / 9 = 230
2300 / 10 = 230
A weather balloon at Earth’s surface has a
volume of 4 L at 275 K and 760 mm Hg. If
the balloon is released and the volume reaches
4.13 L at 704 mm Hg, what is the temperature?
Answer in units of K.
The temperature : 263.016 K
Further explanationCombined with Boyle's law and Gay Lussac's law
[tex]\tt \dfrac{P_1.V_1}{T_1}=\dfrac{P_2.V_2}{T_2}[/tex]
P1 = initial gas pressure (N/m² or Pa)
V1 = initial gas volume (m³)
P2 = gas end pressure
V2 = the final volume of gas
T1 = initial gas temperature (K)
T2 = gas end temperature
P1=760 mmHg
V1= 4 L
T1 = 275 K
P2=704 mmHg
V1=4.13 L
[tex]\tt \dfrac{760\times 4}{275}=\dfrac{704\times 4.13}{T_2}\\\\T_2=263.016~K[/tex]
Parts of mixture
a / can not be separated
b/ have new properties after they are mixed
C/ form achemicl combination of two or more atoms
Answer:
B- Have new properties after they are mixed
I hope this helps
How many molecules are there of the following compound?
5NaNO3
Answer:
84.99467
Explanation:
This should be the answer.
A rock occupies a volume of 20 cm3 and has a mass of 54 grams. Find the density of this rock
Answer:
2.7 gm/cm cubed
Explanation:
To get the answer, you should divide the mass by the volume or 54 divided by 20 = 2.7
A sealed 512 cm3 flask is full to capacity with 16 g of a substance. Determine the density of the substance.
Answer:
The answer is 0.031 g/cm³Explanation:
The density of a substance can be found by using the formula
[tex]density = \frac{mass}{volume} \\[/tex]
From the question
mass = 16 g
volume = 512 cm³
We have
[tex]density = \frac{16}{512} = \frac{1}{32} \\ = 0.03125[/tex]
We have the final answer as
0.031 g/cm³Hope this helps you
A metal block, 2.0cm x 2.5cm x 3.0cm, has a mass of 40.5g. What is the density of the sample? What type of metal is the metal block composed of?
Aluminum - 2.699
Copper - 8.92
Iron - 7.874
Lead - 11.43
Nickel - 8.908
Tin - 7.265
Zinc - 7.14
Answer:
The block is made up of aluminum.
density = 2.7 g/cm³
Explanation:
Given data:
Dimension of metal block = 2.0 cm×2.5 cm× 3.0 cm
Mass of block = 40.05 g
Density of block = ?
Which metal is this = ?
Solution:
Density:
Density is equal to the mass of substance divided by its volume.
The symbol used for density is called rho. It is represented by ρ. However letter D can also be used to represent the density.
Units:
SI unit of density is Kg/m3.
Other units are given below,
g/cm3, g/mL , kg/L
Formula:
D=m/v
D= density
m=mass
V=volume
Volume of block = 2.0 cm×2.5 cm× 3.0 cm = 15 cm³
d = m/v
d = 40.5 g/ 15 cm³
d = 2.7 g/cm³
The block is made up of aluminum.
Answer quick please.
5 Which of the charts below is most likely to represent a saturated solution?
A Chart A
B. Chart B
C. Chart C
D. Chart D
Answer:
c chart c
Explanation:
saturated solution: A solution with solute that dissolves until it is unable to dissolve anymore, leaving the undissolved substances at the bottom.
The chart which represents the graph for the saturated solution is chart C, because in that graph extra solutes are present at the bottom.
What is saturated solution?Saturated solutions are those solutions in which all solutes will dissolve in the solvent and addition of extra solute will not dissolve in the solution, but gets settle down at the bottom of the solution.
Chart A, B and D shows the graph for the unsaturated soution because all solute particles are completely dissolve in the solution and no extra solutes are present in that.Chart C shows the graph for the saturated solution as extra solutes are settle down at the bottom.Hence chart C shows the saturated solution.
To know more about saturated solutions, visit the below link:
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