please answer the question
Answer:
Stamens
Explanation:
What does a negative AHf for a molecule mean?
A. Energy was added when the molecule changed phases.
B. Energy was added when the molecule was formed from its
elements.
C. Energy was released when the molecule was formed from its
elements.
O D. Energy was released when the molecule went through a phase
change.
SUBMIT
Option D I got it right
ANSWER: C (ENERGY WAS RELEASED WHEN THE MOLECULE WAS FORMED FROM ITS ELEMENTS.)
HOPE THE OTHER PERSON IS WRONG!
what do elements and molecules have in common
Explanation:
When elements combine, they form molecules. Simply put, a molecule is a group of two or more atoms chemically bonded together.
The Texas Hill Country ecosystem supports a variety of organisms. Animals such as owls, coyote, snakes and hawks compete for small animals for food. What might happen if the population of these predators became too large? The predators would share the prey population equally among all of the predator species. The predators would begin to eat plants rather than their usual prey. The predators would have more offspring of great size. The predators would consume the prey population faster than it could be replaced.
Answer:
The predators would consume the prey population faster than it could be replaced.
Explanation:
According to Oxford dictionary; an ecosystem is "a biological community of interacting organisms and their physical environment."
An ecosystem is a self supporting unit that is composed of living and non living parts. The ecosystem should be self sustaining.
In the particular case mentioned in this question, when the predator population becomes so large, they will steadily diminish the prey population faster it can be replaced thereby distorting the balance of the ecosystem.
I really need help please and thank -you which two countries has dominated space exploration during the space race from 1955 to 1975
state 5 uses of water in the diet
Answer:
It helps create saliva.
It regulates your body temperature.
It protects your tissues, spinal cord, and joints.
It helps excrete waste through perspiration, urination, and defecation.
It helps maximize physical performance
How do you determine if an equation is balanced or unbalanced.
Difference between Displacement and Double Displacement reaction
Answer:
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Explanation:
A displacement reaction is the one when a more reactive substance displaces a less reactive one from its salt solution whereas a double displacement reaction is the one where a mutual exchange of ions happens between two compounds.
What are the products of the following neutralization reaction? (No need to balance)
H2CO3 + NaOH --> ???? ????
A.)H2O + Na2CO3
B.)H30+ + NaCO3
C.)H20 + NaCO3
D.)H30+ + Na2CO3
H2CO3 + NaOH --> Na2CO3 + H2O
Here salt is Na2CO3.
So, (A) H2O + Na2CO3 is your answer.
An equinox occurs when the:
sun is farthest away from the equator
sun is directly over the equator
north pole is tilted away from the sun
south pole is tilted away from the sun
Answer: sun is directly over the equator
Explanation:
There are only two times of the year when the Earth's axis is tilted neither toward nor away from the sun, resulting in a "nearly" equal amount of daylight and darkness at all latitudes.
how do you use subscripts and coefficients to determine the number of atoms in a molecule.
Answer:
To find out the number of atoms: MULTIPLY all the SUBSCRIPTS in the molecule by the COEFFICIENT. (This will give you the number of atoms of each element.)
Explanation:
61 Cu
29
Write the complete nuclear equations for alpha absorption
Answer:
⁶¹₂₉Cu + ⁴₂He --->⁶⁵₃₁Ga
Explanation:
Nuclear reactions are reactions which occur with changes in the nucleus of an atom. Nuclear reactions usually occur with the release of large amounts of energy and radiation. Radiactive elements are elements that are involved in nuclearbreactions due to the unstable nature of their nucleus. They disintegrate spontaneously with the emission of radiations. The major types of radiations released during nuclear reactions are;
1, Alpha particles - these are positively charged radiations with strong ionizing power. Each alpha particle is a helium nucleus
2. Beta particles - these are very fast moving stream of electrons. They are negatively charged particles .
3. Gamma radiation - is a form of electromagnetic radiation.
In the alpha absorption of Cu-61, the proton number of the atom increases by 2 while the mass number increases by 4 and the Cu-61 atom is changed to Ga-65 atom. The nuclear equation is given as follows:
⁶¹₂₉Cu + ⁴₂He --->⁶⁵₃₁Ga
HELP ME GUYS I NEED HELP RN
Answer:
Robot 1 : 150 J
Robot 2: 40 J
Explanation:
30 N x 5m = 150 J
20 N x 2m = 40 J
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Look at the picture below. What is the name of the copper salt?
Answer:
The reaction took place is-
Fe + CuSO4 → Fe(SO4) + Cu
the copper salt name is copper sulphate!
The statement describes the name of the copper salt is "copper sulphate."
What are salt?A salt is an ionic substance that is created when a positively charged ion bonds with a negatively charged ion.
The reaction occurred in the context of the image.
Fe + CuSO4(aq) → FeSO4(aq) + Cu(s)
A single displacement reaction is the sort of reaction. In this reaction, the highly reactive metal iron oxidises and creates ferrous sulphate by replacing the copper in copper sulphate by giving up two electrons.
Hence the correct answer is copper sulphate.
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which of these phenomena cause uneven heating of the earth
Land and water have different heat capacities
Land and water have the same rate of heat absorption
The angle of incoming sunlight varies at different places
Air travels from areas of low pressure to areas of high pressure
Winds blow in the same direction across Earth's Surface
Answer:
The angle of incoming sunlight varies at different places
Answer: This answer is multiple choices.
1. Land and water have different heat capacities.
And
3. The angle of incoming sunlight varies at different places.
Explanation: I kept seeing other people only putting in one answer, so I used this answer from someone else. Credit to them!
Difference between electro positive and electronegative radical
Answer:
Here's your answerExplanation:
The key difference between electropositive and electronegative radicals is that electropositive radicals are radical compounds having the capacity to electrons and carry a positive charge whereas electronegative radicals are radical compounds having the capacity to gain electrons and carry a negative charge.
I hope it's helpful for you
A gas confined in a 515cm3 container exerts a pressure of 107.4kPa at 38.6⁰C. At what Celsius temperature will it exert a pressure of 635.7kPa if it is placed into a 644cm3 container?
Answer: The temperature at pressure of 635.7 kPa is [tex]2033^0C[/tex]
Explanation:
The combined gas equation is,
[tex]\frac{P_1V_1}{T_1}=\frac{P_2V_2}{T_2}[/tex]
where,
[tex]P_1[/tex] = initial pressure of gas = 107.4 kPa
[tex]P_2[/tex] = final pressure of gas = 635.7 kPa
[tex]V_1[/tex] = initial volume of gas = [tex]515cm^3[/tex]
[tex]V_2[/tex] = final volume of gas = [tex]644cm^3[/tex]
[tex]T_1[/tex] = initial temperature of gas = [tex]38.6^0C=(38.6+273)K=311.6K[/tex]
= final temperature of gas = ?
Now put all the given values in the above equation, we get:
[tex]\frac{107.4\times 515}{311.6}=\frac{635.7\times 644}{T_2}[/tex]
[tex]T_2=2306K=(2306-273)^0C=2033^0C[/tex]
The temperature at pressure of 635.7 kPa is [tex]2033^0C[/tex]
You are performing a reaction involving the collection of a gas at SATP. If 5.00 g of magnesium is added to 100.0 cm3 of 0.100 mol dm−3 HCl, determine the volume of hydrogen gas that will be collected at SATP.
Answer: The volume of hydrogen produced is 0.122 L
Explanation:
To calculate the moles :
[tex]\text{Moles of solute}=\frac{\text{given mass}}{\text{Molar Mass}}[/tex]
[tex]\text{Moles of solute}={\text{Molarity}}\times {\text{Volume in L}}[/tex]
[tex]\text{Moles of} Mg=\frac{5.00g}{24g/mol}=0.208moles[/tex]
[tex]\text{Moles of} HCl=[/tex][tex]0.100moldm^{-3}\times 0.1dm^3=0.01mol[/tex]
The balanced chemical equation is:
[tex]Mg+2HCl\rightarrow MgCl_2+H_2[/tex]
According to stoichiometry :
2 moles of require = 1 mole of
Thus 0.01 moles of [tex]HCl[/tex] will require=[tex]\frac{1}{2}\times 0.01=0.005moles[/tex] of [tex]Mg[/tex]
Thus is the limiting reagent as it limits the formation of product and is the excess reagent.
As 2 moles of give = 1 mole of
Thus 0.01 moles of [tex]HCl[/tex] give =[tex]\frac{1}{2}\times 0.01=0.005moles[/tex] of [tex]H_2[/tex]
According to ideal gas equation:
[tex]PV=nRT[/tex]
P = pressure of gas = 1.0 atm (SATP)
V = Volume of gas = ?
n = number of moles = 0.005
R = gas constant =[tex]0.0821Latm/Kmol[/tex]
T =temperature =[tex]25^0C=(25+273)K=298K[/tex] (SATP)
[tex]V=\frac{nRT}{P}[/tex]
[tex]V=\frac{0.005mol\times 0.0820 L atm/K mol\times 298K}{1.0atm}=0.122L[/tex]
Thus volume of hydrogen produced is 0.122 L
Sublimation is snow or ice changing to a gas without melting. What must happen to the molecules for this to happen?
Answer:Sublimation is the conversion between the solid and the gaseous phases of matter, with no intermediate liquid stage. For those of us interested in the water cycle, sublimation is most often used to describe the process of snow and ice changing into water vapor in the air without first melting into water.
Explanation:
The combustion of ethene,C2H4,is an exothermic reaction. Use the information below to determine the amount of energy given off when 1000g of ethene is conbusted C2H4+3 O2-> 2CO2 + H20
Answer:
[tex]Q=-50,307kJ[/tex]
Explanation:
Hello there!
In this case, since following reaction:
C2H4+3 O2-> 2CO2 + 2H2O
Has an enthalpy of combustion of ethene is about -1411.1 kJ/mol (can be found on goo gle), it is possible to calculate the total amount of energy that is released when 1000 grams of ethene are burned as shown below:
[tex]Q=-1411.1 \frac{kJ}{molC_2H_4} *\frac{1molC_2H_4}{28.05gC_2H_4}*1000gC_2H_4 \\\\Q=-50,307kJ[/tex]
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Use the word bank to complete the charts about the metrics system measurement
Answer:
Length
- centimetre
- millimetre
- kilometre
- meter
Mass
- gram
- kilogram
Capacity
- liter
- millilitre
I don't know why mass is there but hope this helps! :)
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riodic table
2
c table
Which one is more reactive out of Fluorine and Chlorine? Why?
A small portion of Modern periodic table (Group 1) is given. Givet
hydrogen along with metals in this
group.
3. Elements of
group 1, 2, 13 are more reactive as we go down in the
table, why?
Modern periodic table is less defective than Mendeleev's periodic
to justify it.
Group-C
eley's per
Mention any three characteristics of Mendeleev's periodic table.
Write down the three drawbacks of Mendeleev's periodic table.
Write down three characteristics of Modern periodic table.
Which group of the periodic table does the element ‘A’ belong to
reactive in between 'B' and 'C'? Give reason.
Element
Electronic configuration
А
2,8,5
B
2,3
C С
2,8,3
Identify the groups of the alkali metals, metalloids and inert g
8
What is the valency of chlorine and neon? Why?
2
13
14
15
16
17
please help this is very important
Answer:
B
Explanation:
A scientist performs an investigation in which thermal energy is removed from a sample of a substance. When the substance begins to change from a gas to a liquid, the scientist measures the temperature of the substance. This temperature is the substance's
A. melting point
B. freezing point
C. evaporation
D. condensation
2
The table gives the melting and boiling points of four pure substances, W, X, Y and Z.
Melting point in °C
Boiling point in °C
w
-7
60
Х
660
2500
Y
180
1330
Z
115
445
Use data from the table to answer the questions.
(a) (0) Which substance is a gas at 100°C?
X AW
B X
D CY
DZ
(ii) Which substance is a liquid for the largest range of temperature?
D A W
B X
CY
DZ
liquid at 1000 °C and a gas at 2000°C?
Answer:
(a) W
(b) X
(c) Y
Explanation:
Let's consider the following table with melting and boiling points for 4 substances.
Substance Melting Point (°C) Boiling Point (°C)
W -7 60
X 660 2500
Y 180 1330
Z 115 445
Let's consider that:
Below the melting point, a substance is solid.Between the melting and the boiling point, a substance is liquid.Above the boiling point, a substance is gas.(a) Which substance is a gas at 100°C?
At 100 °C, W is above the boiling point
(b) Which substance is a liquid for the largest range of temperature?
The largest difference between the melting point and the boiling point is that of X: 2500 - 660 = 1840.
(c) Which substance is liquid at 1000 °C and a gas at 2000°C?
Y is between the melting and the boiling point at 1000 °C and above the boiling point at 2000 °C.
which non metal is a good conductor of heat and electricity ?
Answer:
Graphite
Graphite is a non-metal and it is the only non-metal that can conduct electricity. You can find non-metals on the right side of the periodic table and graphite is the only non-metal that is a good conductor of electricity.
Answer:
Graphite is a non metal which is a good conductor of heat and electricity .
hope it is helpful to you
Name the following compound: C2Cl6
Why does water float on corn syrup
Answer:
density.
Explanation:
A cubic centimeter of water weighs 1 gram. Since a cubic centimeter of vegetable oil weighs less than 1 gram, oil will float on water. Corn syrup is more dense than water so 1 cubic centimeter of corn syrup weighs more than 1 gram. Therefore, corn syrup sinks in water.
Answer:
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Which of the following birds is not a second-order prairie consumer?
owl
falcon
eagle
pheasant
which statement best describes a chemical property related to the particles that make up a material
A. nickel is a good conductor of electricity because the metallic bonds between its atoms allow electrons to move freely.
B. demand is a hard substance because its atoms are joined together by covalent bonds.
C. metallic bonds between its ions cause silver to be a highly malleable material.
D. chlorine is highly reactive with other elements because its atoms have 7 valence eletrons.
The statement that best describes a chemical property related to the particles that make up a material is A) nickel is a good conductor of electricity because the metallic bonds between its atoms allow electrons to move freely. Option A
Chemical properties describe how substances undergo chemical reactions or interactions with other substances. In this case, the statement about nickel highlights a specific chemical property related to its ability to conduct electricity.
Nickel is a metallic element with a unique atomic structure. It possesses metallic bonds, which involve the sharing of electrons between atoms within a metal lattice. In metallic bonding, the valence electrons of metal atoms are delocalized, meaning they are not strongly associated with any specific atom but are free to move throughout the material.
The presence of these mobile electrons in nickel enables it to conduct electricity effectively. When a potential difference is applied across a conductor like nickel, the mobile electrons can move in response to the electric field, carrying electrical charge from one point to another.
Option B) is incorrect because hardness is a physical property related to the arrangement and bonding of atoms, not a chemical property.
Option C) is also incorrect because malleability is a physical property resulting from the ability of metal atoms to slide past each other when a force is applied, not a chemical property.
Option D) describes the electronic configuration of chlorine, which is a characteristic of its atom but does not directly relate to a chemical property associated with the particles that make up a material.
In summary, option A best describes a chemical property related to the particles that make up a material, specifically nickel's ability to conduct electricity due to the presence of mobile electrons enabled by metallic bonds.
Option A
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