Answer:
Moving Across a Period
Moving from left to right across a period, the atomic radius decreases. The nucleus of the atom gains protons moving from left to right, increasing the positive charge of the nucleus and increasing the attractive force of the nucleus upon the electrons
An object with a negative acceleration could NEVER have a positive velocity. a. TRUE b. FALSE
Answer:false
Explanation:
How could the survivors about starting a fire?
What is fire?Describe it.
What makes a fire hot?
Answer:
The ancient Greeks believed that fire was one the four basic elements that composed all things in the universe. In the mythology of virtually every culture, fire is a sacred substance that gives life or power. Fire is not, in fact, a substance. When you gaze at the leaping flames of a campfire, you’re observing not an object, but a process – a chemical reaction. It’s the same chemical reaction that occurs when a cut apple left on the counter turns brown, when silver tarnishes or when an iron nail rusts.
That process is oxidation: combining oxygen with another substance. The defining difference between a fire and your half-eaten apple is speed: fire is an oxidation process that happens very fast, so that light, heat and sound are released — often with enough force and majesty to justify the ancients’ reverence.The sudden release of energy causes temperatures to rise, sometimes by thousands of degrees. And it also results in smoke, the toxic waste of fire’s leftovers.
The fire triangle and the fire tetrahedron
Fire TetrahedronThe fire triangle identifies the three needed components of fire:
fuel (something that will burn)
heat (enough to make the fuel burn)
and air (oxygen)
Explanation: i hope this helps sry its long
Find 6 examples of where chemistry and agriculture work together
Answer:
Chemistry deals with compounds, both organic and inorganic, and agriculture deals with the production of organic products using both organic and inorganic inputs Thus Chemistry forms an integral part of agriculture from molecular to organ level.
Explanation:
i hope this helps you! Have a nice day <33
Answerfcsdv fb fd
Explanation:
Which best explains how fiber-optic technology benefits the field of medicine?
O It allows doctors to view internal body structures to help them diagnose illnesses.
O It helps surgeons make more accurate repairs to broken blood vessels.
O It allows doctors to magnify cells so they can identify unhealthy cells that cause cancer.
O It helps surgeons make cuts that are smaller and less painful than traditional methods.
Answer:
A. It allows doctors to view internal body structures to help them diagnose illness.
Explanation:
The statement, that describes fiber-optic technology benefits the field of medicine is "it allows doctors to view internal body structures to help them diagnose illnesses."
What is fiber-optic technology?Fiber optics is a technology that transmits information as light pulses across great distances using strands of glass or plastic fibre. Fiber-optic cables use light pulses that travel quickly to convey data.
Internal organs and tissue can be viewed through bodily orifices because to the flexible yet hard multi-fibers. Endoscopes are used by doctors to explore symptoms such as nausea and gastrointestinal pain, confirm diagnosis through biopsies, and provide medical therapy.
Medical fibre optics are an important medical technology that is employed in a variety of medical professions. They are chemically inert, sterile, malleable, and non-toxic to the human body. Fiber optic technology enables surgeons to repair organs, diagnose joint problems, and remove sick tissues, resulting in a faster recovery period for the patient than more intrusive surgical approaches.
Hence the correct answer is it allows doctors to view internal body structures to help them diagnose illnesses.
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what tool would a scientist use to study fish eggs
Answer
1. Magnifier glass.
2. Ruler.
3. Scale.
Explanation:
1. To look and enspect the fish egg's.
2. To see how long and tall the fish egg's are.
3. To weight how heavey the fish egg's are.
Magnifier glass, scale, and ruler tools would a scientist use to study fish eggs
To look and inspect the fish egg's scientists will use the magnifier glass . To see how long and tall the fish's eggs are, scientists will use scale. To measure the weight of the fish eggs, scientists will use a ruler.
Hence, Magnifier glass, scale, and ruler tools would a scientist use to study fish eggs.
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What structures are present in a animal cell but not in a plant cell?
Animal cells each have a centrosome and lysosomes, whereas plant cells do not. Plant cells have a cell wall, chloroplasts and other specialized plastids, and a large central vacuole, whereas animal cells do not.
Define Chemotherapy
Explanation:
the treatment of disease by the use of chemical substances, especially the treatment of cancer by cytotoxic and other drugs.
A true statement about mass is that
A. as the force of Earth's gravity on an object increases the object's mass increases.
B. mass is expressed in pounds
C. mass if often measured with a spring scale. D. mass is determined by comparing the mass of an object with a set of standard masses tha catalanse
Answer:
d
Explanation:
A: mass never increases or decreases. It is a value that is the same everywhere in the universe. A is not correct.
B: it can be but that is not the only unit that can be used
C: A spring scale measures force not mass.
D: The answer to this question is D if the word at the end is balance.
An object measures 6.2cm x 13.7cm x 26.9cm. Which value is the length of the object?
Answer:
Explanation:
The length is usually the longest side.
That would mean that 26.9 is the length.
What is the answer to this question
Answer:
hypothesis
Explanation:
a hypothesis is a prediction that you make about an experiment.
_________ is the mechanical separation of a mixture based upon the sizes of the mixtures components.
Answer:
Sieving
Explanation:
Sieving is a mechanical separation technique which depends on the relative sizes of particles in the mixture.
A mesh is used to discriminate between particle sizes. Particles in the mixture which are larger than the mesh size do not pass through the sieve, hence particles whose size is less than that of the mesh are separated from the rest of the particles in the mixture.
15 x 10^2) + (5.2 x 10^5)
Explanation:
(15 × 10^2) =1500.
(5.2 ×10^5)=520000.
(1500)+(520000).
=518500 .
What is a molecular orbital? Question 3 options: Another method of describing the orbitals of individual atoms A mixing of the atomic orbitals from an atom’s inner-most shell with those of the valence shell An area around a molecule that describes a region of space where the electrons that are shared between bonded atoms can reside A mixing of the atomic orbitals from an atom’s valence shell
Answer:
An area around a molecule that describes a region of space where the electrons that are shared between bonded atoms can reside
Explanation:
A molecular orbital is an area around a molecule that describes a region of space where the electrons that are shared between bonded atoms can reside.
Molecular orbitals are formed by linear combination of atomic orbitals of about the same energy. The number of atomic orbitals that are combined to give molecular orbitals is the same as the number of molecular orbitals formed. The build up of electrons in molecular orbitals also follow the Aufbau principle, Hund's rule and Pauli exclusion principle.
The accepted value for the molar volume of a gas is 22.4 L. Sarah’s experimental data indicated that a mole of a gas had a volume of 19.6L. What was her percent error?
Answer:
12.5%.
Explanation:
The following data were obtained from the question:
Accepted value = 22.4 L
Experimental value = 19.6L
Percentage error =.?
Percentage error can be obtained by using the following formula:
Percentage error = |Experimental value – Actual value | / actual value × 100
Percentage error = |19.6 – 22.4|/22.4 × 100
Percentage error = 2.8 /22.4 × 100
Percentage error = 280/22.4
Percentage error = 12.5%
Therefore, the percentage error of Sarah is 12.5%
A gas absorbs 10J of heat and is simultaneously
compressed by a const and external pressure
of 0.5 atm from 4L to 2L in volume What
is the change in the internal energy.
A. 101J b. 111J c.2J d. none of the above
Given :
Heat absorbs , Q = 10 J .
Pressure , [tex]P=0.5 \ atm =0.5\times 101325\ Pa[/tex]
Initial volume , [tex]V_i=4\ L[/tex] .
Final volume , [tex]V_f=2\ L[/tex] .
To Find :
The change in the internal energy .
Solution :
By first law of thermodynamics :
[tex]\Delta U=Q+W[/tex]
Here , W is work done , [tex]W=-P\Delta V=-P\times (V_f-V_i)[/tex]
Therefore,
[tex]\Delta U=Q-P(V_f-V_i)[/tex]
Putting values in SI units in above equation :
[tex]\Delta U=10 -(0.5\times 101325\times (2-4)\times 10^{-3})\\\\\Delta U=111\ J[/tex]
Therefore , option b. is correct .
Hence , this is the required solution .
Classify the following changes as physical or chemical changes. a. Water boils. b. Salt dissolves in water c. Milk turns sour d. A metal rusts.
Answer:
Water boils - physical change
Salt dissolves in water- chemical change
Milk turns sour- chemical change
metal rusts - chemical change
Explanation:
A chemical change refers to changes that are irreversible and the process involves the evolution of heat along with the formation of a new substance, examples include;Salt dissolves in water, Milk turns sour, metal rusts etc
The boiling of water is a physical change. The water can be cooled and the vapour condensed,hence, the boiling of water is a physical change.
Physical changes are easily reversible and no new substance is formed.
Search blue bottle experiment, read over the reaction, and explain why the colorless solution turns blue
and how it then turns back to colorless. answer
Answer:
An alkaline solution of glucose acts as a reducing agent and reduces added methylene blue from a blue to a colourless form.
Where is altitude measured in meters? How did this affect the MD-11?
Answer:
China, Mongolia, Russia, and North Korea. They were told to fly at 1400 meters but they flew at 1500 feet making them crash.
Explanation:
When a change in a physical property is observed, Select the correct answer below: it could be because of a physical change. it must be because of a chemical change. it must be because of a chemical change and a physical change. it could be caused by a change that is considered both physical and chemical.
Answer:
It could be because of a physical change.
Explanation:
A physical change affects a substance's physical properties, and a chemical change affects its chemical properties.
Why was lake Lenore chosen
Answer:
Dude just watch the video
Explanation:
which part of potato plant stores food?
Answer:
Explanation:
The answer is rooot ok
the food is prepared in the form of starch in potato and ginger plants the food is stored in the Ender Ground Park gender and potato or underground stems while potato is a tuber Ginger is a rhizome in the food is stored in them in the form of starch so it is prepared in the leaves.
Which of the following is not a step of the scientific method ?
A)Testing the hypothesis by experiments
B)making observations that lead to a question
C)forming a hypothesis to answer the question
D)changing the data to fit your hypothesis
Answer:
b
Explanation:
Note that : Hypothesis can be regarded as proposed explanation needed for a phenomenon.
The steps involves in scientific method are:
Making of observation about the topic that is needed to study. this is necessaryAsking of particular question ; once once background information has been gained about the topic then question needs to be asked and here hypothesis is formed by researcher, which gives relationship between variables.Testing of hypothesis and data collection, in this step the hunch is been put to test and use different method to collect needed data.Examination of result and drawing of conclusion. Once study has been designed by researcher and data has been collected it is time to examine those information and draw a conclusion.Learn more at: https://brainly.com/question/497944
The least abundant gas in the air is
a. Xenon, Xe
b. Oxygen, O2
c. Water, H2O
d. Nitrogen, N2
Answer:
A.
Explanation:
Two or more than two atoms with different physical or chemical properties can not combine together to form an element. Xenon(Xe ) is the least abundant element on the earth. The correct option is option A.
What is element?Element generally consist of atoms or we can atoms combine to form element. Atoms of an element is always same, means all the properties of all atoms of one type of element is same.
Oxygen, water, and nitrogen are the most abundant molecule on the earth. Xenon is the least abundant amongst all given option. Xenon belongs to noble gas family. So, Xenon is not reactive at all. Xenon does not form any compound with any other element so its abundance on earth is very less.
Therefore, Xenon(Xe ) is the least abundant element on the earth. The correct option is option A.
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Why can't scientific method always be used to solve social, political, ethical, and economic problems?
Answer:
In fact, science helps a lot for social, political, ethical, and economic problems. Your question is just to deny that science is not helping your life and you have no evidence to support what you say.
Explanation:
can anyone do these problems?
Answer:
-76
296
228
603
485
Explanation:
Subtract 273 to 200 to get -76
add 273 to 23 to get 296
add 273 to -45 to get 228
subtract 273 to 876 to get 603
add 273 to 212 to get 485
iron is a metal that rusts in the presence of oxygen and water. mild steel is used for ...1... and is prevented from rusting by ...2...chemistry igcse
Answer and Explanation:
Used as a construction frame material and for bending metal works because they are rigid and strong.Galvanising or coating the surface would prevent rusting.N.B.: Mild steel is steel that has low carbon content, also called carbon steel.
I hope this explanation was helpful.
Answer:
car bodiespaintingExplanation:
Mild steel is used in making car body parts because it is malleablePainting mild steel prevents moisture and oxygen from reaching the metalIn a chemical processing plant, a reaction chamber of fixed volume V0 is connected to a reservoir chamber of fixed volume 4V0 by a passage containing a thermally insulating porous plug. The plug permits the chambers to be at different temperatures. The plug allows gas to pass from either chamber to the other, ensuring that the pressure is the same in both. At one point in the processing, both chambers contain gas at a pressure of 1.00 atm and a temperature of 27.0°C. Intake and exhaust valves to the pair of chambers are closed. The reservoir is maintained at 27.0°C while the reaction chamber is heated to 400°C. What is the pressure in both chambers after that is done? 50. Why is the following situation impossible?
Answer:
Explanation:
The two chambers are at temperature of 27° and pressure of 1 atm . Now temperature of second chamber is increased to 400°C so its pressure will be increased but pressure of chamber whose temperature remains at 27°C will remain unaltered . Hence the pressure of chamber at 27°C will be at 1 atm.
The volume of second chamber is 4 V₀ , temperature changed from 27 + 273 = 300 k to 400 + 273 = 673 K , initial pressure was 1 atm . Let final pressure be P
From gas law formula
1 x 4 V₀ / 300 = P x 4 V₀ / 673
P = 1 x 673 / 300
= 2.24 atm .
The pressure of the chamber at 400°C will be 2.24 atm.
Which of these describes a natural phenomenon or relationship that always occurs under specific conditions a) theory b) law Group of answer choices
Answer:
B). Law
Explanation:
A law is defined as the statement of an observed order, sequence, or relationship of a natural phenomenon which is invariable or always true under certain specific conditions while the theory is characterized as the explanation of this observed phenomenon and prediction of the new facts or phenomenon which was previously not observed to set out the new laws or principles of something. Thus, the theory is the base for the formation of law and hence, option B is the correct answer.
the valency of metal 'm' 1+. give the formula of its oxide
Answer:
[tex]M_{2}O[/tex]
Explanation:
Anything oxide is a compound with oxygen, and since oxygen is -2, it requires two of the metal's +1 to make it zero
In other words:
2(+1) + (-1) = 0
use the density formula to solve the following problems. a sample of a substance has a volume of 60.5mL and a density of 1.20mL. What is the mass of the sample?
Answer:
mass of substance =50.4 g
Explanation:
Using the density formula;
Density = mass of substance / volume of substance
Therefore, making mass subject of the density formula,
mass of substance = volume of substance / density of substance
volume of substance = 60.5 mL, density = 1.20 g/mL ( since common units of density is either g/cm³ or g/mL)
mass of the substance = 60.5 mL / 1.20 g/mL
mass of substance = 50.4 g