Answer:
Atomic number of a chemical element is the number of protons found in the nucleus of every atom of that element.
The mass number, also called atomic mass number or nucleon number, is the total number of protons and neutrons in an atomic nucleus.
The atomic nucleus is the small, dense region consisting of protons and neutrons at the center of an atom.
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:
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
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
Why do most metals exist in nature as minerals rather than as pure metallic elements?
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
Question: Give the name for
the following compounds
1. MgF2
2. C2H6
3. Fe203
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.
6. Now, revise your definition for waves to include energy and matter.
A wave is a phenomenon that...
Answer:
A wave is phenomenon that transfers energy from one point to another through a disturbance without affecting the matter.
Explanation:
A wave is phenomenon that transfers energy from one point to another through a disturbance without affecting the matter.
There are two main types of waves Longitudinal waves travels parallel to their source. For example, sound waves. Through a series of rarefactions and compressions, longitudinal waves are propagated. Transverse waves travel perpendicular to their source.What accounts for the attractions in a chemical bond?
Answer:
A chemical bond is a lasting attraction between atoms, ions or molecules that enables the formation of chemical compounds. The bond may result from the electrostatic force of attraction between oppositely charged ions as in ionic bonds or through the sharing of electrons as in covalent bonds.
Explanation:
How many moles of Al are there in 20g of Al2(C2O4)3?
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
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!
helppppppppppppp plzzzzzzzz Identify each structure based on its label.
Compound A is a
amine.
Compound B is a
amine.
Compound C is a
amine.
Compound D is
.
Answer:
kldja
Explanation:
A.) primary
B.) tertiary
C.) secondary
D.) ammonia
edge2020
GIVING 5 STARS AND BRAINLY IF YOU ANSWER FIRST AND CORRECTLY
Please answer asap. Thank you.
QUESTION:
How many total elements are involved in the process of photosynthesis?
A. 2
B. 3
C. 4
D. 5
Provided is a diagram showing forces on a box.
Left
Right
40 Newtons
35 Newtons
What is the net force on the box?
SN Leht
O5N Right
75 N Let
O 75 N Right
please hurry i’m taking a test
Answer:
5 N left
Explanation:
trust me cccuuhh
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:
Your science teacher removed the gas from a birthday balloon. They discovered that the gas is made of the element helium. Inside that atom is:
A. A new substance
B. Protons, neutrons and electrons
C. A different element
D. All of the above
An element, X, has 2 isotopes, X-32 with an abundance of 31.5% and X-35 with an abundance
of 68.5%. What is the average atomic mass of element X?
Answer:
amu = 34.055 or 34.1
Explanation:
to calculate the average mass, first convert the percentages into decimals. Then, calculate the mass numbers. To get this number, multiply the decimal by the mass number for each isotope and, then add them together.
( 0.315 x 32 ) + (0.685 x 35 ) = 34.055
The volume of a candy bar is 55cm^3. The mass of the candy bar is 70g. What is the density of the candy bar in g/cm^3
Answer:
1.3 g/cm3
Explanation:
Different elements have different numbers of:
Subatomic particles.
Protons.
Electrons.
All of the above.
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 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:
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!!!
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
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
What is the formula for an alkene containing six carbon atoms?
A. C6H10
B. C2H6
C. C6H12
D. C5H12
Answer:
C
Explanation:
Cyclohexane is a cycloalkane with the molecular formula C₆H₁₂. Cyclohexane is non-polar.
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:
............
Name for each compoud
1.CO
2.H2SO4
3CaCO3
4 H202
5NaF
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
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