Answer:
Explanation:
Noble gases are the least reactive of all known elements. That's because with eight valence electrons, their outer energy levels are full. The only exception is helium, which has just two electrons.
Which of the following best describes hair? O Hair is made of mostly tightly packed living cells Hair does not help control body temperature. O Hair growth occurs in the hair follicle O Hair grows at 2.5mm a month.
Answer:
(A) Hair is made of mostly tightly packed living cells.
Explanation:
i just took the exam :) yw
a like would be nice thanks!
Answer:
A
Explanation:
Just did the exam :) Good Luck!
express the answer to each of the following calculations in scientific notation with the correct number of significant figures: 45.0 x 270
Answer: 1.215 × 10^4 i think
Explanation:
Which of the samples pictured is most likely a nonmetal?
A moderately shiny grey mineral.
A very shiny silvery mineral.
A crystalline yellow mineral.
A very shiny golden mineral with many small crystals.
Answer:
i think it is C
Explanation:
sorry if wrong
does breast cancer occur in women? what are the signs and symptoms ?
actually anatomy & physiology own words pls i need it now
Answer:
Breast Cancer occurs in a lot of women.
Explanation:
The following are some symptoms of breast cancer in women.
New lump in the breast or underarm (armpit).
Thickening or swelling of part of the breast.
Irritation or dimpling of breast skin.
Redness or flaky skin in the nipple area or the breast.
Pulling in of the nipple or pain in the nipple area.
Nipple discharge other than breast milk, including blood.
Another thing is that women each year after age 40 are encouraged to get a mamogram.
Answer:
yes breast cancer can occur in both men and women.
Explanation:
some warning signs can be feeling a new lump on or around the breast or in the arm pit area, swollen or redness, also discharge from the nipple can be a sign of breast cancer. Breast pain that doesn't go away can be a sign of breast cancer.
hope this helps some. have a great night!
How many moles of Al are there in 20g of Al2(C2O4)3?
Could you do both a and b
Answer: a. atominc number= protons= 33
neutrons= mass- atominc number
80-33= 47 neutrons
b.35 protons
46 neutrons
hope this helps
You are conducting an experiment with two very reactive substances. One will react with oxygen (O) and other substances in the air, and the other will react to metal in a container. What type of environment can you seal them in so they only react with each other?
Answer:
seal them in a glass container in an atmosphere of argon (Ar) gas
Explanation:
Explain what lattice energy is and how it affects the properties of ionic compounds. Describe the general properties of ionic compounds.
Answer:
The force of attraction between oppositely charged particles is directly proportional to the product of the charges on the two objects (q1 and q2) and inversely proportional to the square of the distance between the objects (r2).
The strength of the bond between the ions of opposite charge in an ionic compound therefore depends on the charges on the ions and the distance between the centers of the ions when they pack to form a crystal.
An estimate of the strength of the bonds in an ionic compound can be obtained by measuring the lattice energy of the compound, which is the energy given off when oppositely charged ions in the gas phase come together to form a solid.
Explanation:
The lattice energies of ionic compounds are relatively large. The lattice energy of NaCl, for example, is 787.3 kJ/mol, which is only slightly less than the energy given off when natural gas burns.
The bond between ions of opposite charge is strongest when the ions are small.
The ionic bond should also become stronger as the charge on the ions becomes larger.
Answer:
The force of attraction between oppositely charged particles is directly proportional to the product of the charges on the two objects (q1 and q2) and inversely proportional to the square of the distance between the objects (r2). The strength of the bond between the ions of the opposite charge in an ionic compound therefore depends on the charges on the ions and the distance between the centers of the ions when they pack to form a crystal. An estimate of the strength of the bonds in an ionic compound can be obtained by measuring the lattice energy of the compound, which is the energy given off when oppositely charged ions in the gas phase come together to form a solid.
Explanation:
Got it right on edge 2020
Scientists have changed the model of the atom as they have gathered new evidence. One of the atomic models is shown below. A purple center outlined in black with two concentric black circles around the center, the inner circle having 2 small green balls on it and the outer circle having 8 small green balls on it. What experimental evidence led scientists to change from the previous model to this one? A few of the positive particles aimed at a gold foil seemed to bounce back. The colors of light emitted from heated atoms had very specific energies. Experiments with water vapor showed that elements combine in specific proportions. Cathode rays were bent in the same way whenever a magnet was brought near them.
Answer:
B: The colors of light emitted from heated atoms had very specific energies.
Explanation:
dont know if its the same question i had on edg but i think its B. Sorry if i didnt understand the question :)
Answer:
b
Explanation:
The charged particles in the beams that Thomson studied came from atoms. As these particles moved away from their original atoms, they formed a visible beam. The current model of the atom includes protons, neutrons, and electrons. What is the best use of an atomic model to explain the charge of the particles in Thomson's beams? An atom's negative particles are surrounded by positive matter, so the positive particles are easier to remove. An atom's positive particles are surrounded by negative matter, so the negative particles are easier to remove. An atom's smaller negative particles are at a distance from the central positive particles, so the negative particles are easier to remove. An atom's larger positive particles are at a distance from the central negative particles, so the positive particles are easier to remove.
Answer:An atom's positive particles are surrounded by negative matter, so the negative particles are easier to remove.
Explanation:
From our knowledge of the atom, we know that the nucleus lies at the center of the atom. The nucleus is positively charged because it contains the positive particles in the atom
The negative matter (electrons) surround the positive matter (protons) hence it is easier to remove the negative particles compared to the positive particles.
Answer:
C
Explanation:
I need help again LOL.
Answer:
They require diffrent types of atoms for their makeup I belive is the answer Hope this helps
Explanation: Wow you have a lot a questions XD :D :3
Element: A substance that is made up of only one type of atom. Compound: A substance that is made up of more than one type of atom bonded together. Mixture: A combination of two or more elements or compounds which have not reacted to bond together; each part in the mixture retains its own properties.
i hope this helps
how did music change during medieval, renaissance and baroque eras
Answer:
usage of trills and vibrato
Explanation:
earlier music used trills while later styles would use vibrato.
which of the following elements would decrease in size when it became an ion
Answer:
nickel, cobalt would decrease in size when it became an iron
Using the reaction below: 2 CO2(g) + 2 H2O(l) → C2H4(g) + 3 O2(g) ΔHrxn= +1411.1 kJ What would be the heat of reaction for this reaction? 0.5 C2H4(g) + 1.5 O2(g) → CO2(g) + H2O(l) ΔHrxn= ??? KJ Question 6 options: a) Not enough information is given b) -2822.2 kJ c) +1411.1 kJ d) -705.55 kJ e) -1411.1 kJ
Answer: d) -705.55 kJ
Explanation:
Heat of reaction is the change of enthalpy during a chemical reaction with all substances in their standard states.
[tex]2CO_2(g)+2H_2O(l)\rightarrow C_2H_4(g)+3O_2(g)[/tex] [tex]\Delta H=+1411.1kJ[/tex]
Reversing the reaction, changes the sign of [tex]\Delta H[/tex]
[tex]C_2H_4(g)+3O_2(g)\rightarrow 2CO_2(g)+2H_2O(l)[/tex]
[tex]\Delta H=-1411.1kJ[/tex]
On multiplying the reaction by [tex]\frac{1}{2}[/tex] , enthalpy gets half:
[tex]0.5C_2H_4(g)+1.5O_2(g)\rightarrow CO_2(g)+H_2O(l)[/tex][tex]\Delta H=\frac{1}{2}\times -1411.1kJ=-705.55kJ/mol[/tex]
Thus the enthalpy change for the given reaction is -705.55kJ
Regina conducted an investigation to determine whether earthworms add nutrients to soil. She used two pots of soil. She added three earthworms to the first pot. She did not add any earthworms to the second pot, which was the control. Regina tested the nutrient levels of the soil in both pots after two weeks. What type of investigation is Regina conducting?
The question is incomplete, the complete question is:
Regina conducted an investigation to determine whether earthworms add nutrients to soil. She used two pots of soil. She added three earthworms to the first pot. She did not add any earthworms to the second pot, which was the control. Regina tested the nutrient levels of the soil in both pots after two weeks.
What type of investigation is Regina conducting?
descriptive
comparative
experimental
procedural
Answer:
experimental
Explanation:
In an experimental study, there is an independent variable, a dependent variable and a set up meant for control.
The control is set up to establish the validity of the study.
Experiments are designed to establish cause and effect relationship. In this case, the experiment was designed to establish weather earthworms add nutrient to the soil.
Answer:
experimental
Explanation:
experimental
Solid substance A has a melting point of 100°C. Liquid substance B has a freezing point of 110°C. For each substance, identify its state of matter and describe the motion of its particles when the substance is at 115°C.
Answer:
both will be at liquid state. the particles will move rapidly in all directions and will collide with other particles in random motion
Different elements have different numbers of:
Subatomic particles.
Protons.
Electrons.
All of the above.
Why are forecasters able to make more accurate predictions about the weather when using electronic tools?
O A wide variety of devices can be used to collect weather data from many places
O Weather data come exclusively from different weather stations in one region.
Data fed into a supercomputer accounts only for select processes that occur on Earth.
Scientists must input several pieces of weather information into a computer system.
Answer:
option 1
Explanation:
Forecasters, able to make more accurate predictions about the weather when using electronic tools because a wide variety of devices can be used to collect weather data from many places. Therefore, option A is correct.
What is forecaster ?Forecaster behavior is examined by forecasters to see how social, cultural, ethical, and environmental trends will likely impact it. They can determine what goods and services people will be wanting to purchase through this approach.
A person who informs you about the anticipated state of a situation: an analyst of the economy. a forecaster of weather. The term "meteorologist" has now become widely used to refer to someone who forecasts the weather and investigates objects that fall from the sky.
Fitzroy developed charts to allow forecasts to be made, which he called "forecasting the weather," and therefore created the word "weather forecast," after a storm in October 1859 that resulted in the loss of the Royal Charter.
Thus, option A is correct.
To learn more about forecaster, follow the link;
https://brainly.com/question/882902
#SPJ6
How many atoms of each element are in one molecule of 2-heptanone?
Which two substances are among the four major types of organic compounds made by living things?
A. Lipids
B. Carbon dioxide
C. Water
D. Nucleic acids
Answer:
I think carbon.
Explanation:
............
A) saturated
B)desaturated
C)unsaturated
D)supersaturated
Answer:
No Its B Unsaturated becuase the line is slanted
Explanation:
If an object increases in speed, it must be as a result of
o increasing friction.
o unbalanced forces.
O gravitational attraction.
O air resistance.
please hurry i’m taking a test
Answer:
a; increasing fraction
Explanation:
Why do most metals exist in nature as minerals rather than as pure metallic elements?
Select each process that shows a physical change. Select all that apply. Several logs chopped into pieces. Chopping Wood Logs burning as in a campfire. Burning Wood A pot of water on a grate over a burning fire. Heating Water A marshmallow on a stick held above a fire. Roasting Food
Answer:
Chopping wood logsA pot of water o a grate over a burning fireExplanation:
Physical change is easily reversible. Burning/combustion is a chemical process where substances react rapidly with oxygen: this is usually irreversible.
The marshmallow, roasted food and burned wood all undergo combustion and hence are tagged chemical changes.
I hope this helps.
Answer:
Chopping Wood
Heating Water
Explanation:
Which of the following elements has the lowest ionization energy?
A. chlorine (CI)
B. potassium (K)
C. magnesium (Mg)
D.neon (Ne)
Answer:
B. Potassium
Explanation:
Potassium
How does the work needed to lift an object and the gravitational potential energy of the object compare? OThey are equal. OThe work is greater. OThe work is less. OThe comparison dependş on the height.
○ they are equal
○ the work is greater
○ the work is less
○ the comparison depends on the height
Answer:
They are equal
Explanation:
took the test
Answer:
ITS A JUST FINISHED
Explanation:
How does a heat affect the chemical reaction?
Answer:
Increasing the temperature increases reaction rates because of the disproportionately large increase in the number of high energy collisions. It is only these collisions (possessing at least the activation energy for the reaction) which result in a reaction.
Explanation:
How can changes in temperature cause movement of air and other fluids on Earth? , “information I found on the Internet”
Answer:
Winds are a result of the tendency of warm air to rise and, conversely, cool air to sink. ... Because the atmosphere constantly flows, like a fluid in a container, air rushes into such low pressure areas from cooler, high-pressure ones, and the movement of the air creates wind.
Question: Give the name for
the following compounds
1. MgF2
2. C2H6
3. Fe203
When thermal energy is removed from a system, what happens to the
temperature and the average kinetic energy of the system?
Temperature decreases, average kinetic energy increases
Temperature decreases, average kinetic energy decreases
Temperature increases, average kinetic energy increases
Temperature increases, average kinetic energy decreases
Answer:
When the average kinetic energy of the molecules goes up (a rise in temperature), the average speed of the molecules increases. And lower average kinetic energy of the molecules means they have lower speed. ... When heat (energy) goes into a substance one of two things can happen
Explanation:
hope this helpss!!!