Answer:
Barium
Beryllium
Radium
Calcium
Explanation:
Given the standard heats of reaction
Reaction ∆H 0
M(s) + 2 X2(g) → MX4(g) −98.7 kJ/mol
X2(g) → 2 X(g) +327.3 kJ/mol
M(g) → M(s) −20.1 kJ/mol
calculate the average bond energy for a single
M-X bond.
Answer in units of kJ/mol.
Answer:
Explanation:
M(s) → M (g ) + 20.1 kJ --- ( 1 )
X₂ ( g ) → 2X (g ) + 327.3 kJ ---- ( 2 )
M( s) + 2 X₂(g) → M X₄ (g ) - 98.7 kJ ----- ( 3 )
( 3 ) - 2 x ( 2 ) - ( 1 )
M( s) + 2 X₂(g) - 2 X₂ ( g ) - M(s) → M X₄ (g ) - 98.7 kJ - 2 [ 2X (g ) + 327.3 kJ ] - M (g ) - 20.1 kJ
0 = M X₄ (g ) - 4 X (g ) - M (g ) - 773.4 kJ
4 X (g ) + M (g ) = M X₄ (g ) - 773.4kJ
heat of formation of M X₄ (g ) is - 773.4 kJ
Bond energy of one M - X bond = 773.4 / 4 = 193.4 kJ / mole
During which process of the water cycle does water change from gas to liquid
Is the equation C2H4 —> 2C + 2H2 + 52.3 exothermic or endothermic?
Answer:
Exothermic
Explanation:
which element has an atom with the following composition? 24 protons, 28 neutrons and 24 electrons.
Which of the following is an example that includes
evidence of a chemical reaction?
Which of the following has the smallest radius?
A. Br-
B. Br
C. I-
D. I
B) Br
..................
How is iodine 131 similar to a normal atom of iodine?
Answer: Iodine 131 is a radioisotope with a very short half-life of 8.02 days, making it highly radioactive.
Explanation:
A force is always a push. true or false ?
PLEASE HELP ME!!
Water (H2O) is composed of the same elements as hydrogen peroxide (H2O2).
Why do these substances have different properties?
The molecules are the same.
Water has more atoms than hydrogen peroxide.
The atoms are arranged differently in each molecule.
The atoms are the same.
Answer:
The molecules are the same.
Explanation:
What is a scale and why do you use it?
Answer:
Scale is defined as a system or series of marks used for measuring or registering. An example of scale is what someone would use to figure out the length of something. An example of scale is what someone would use to find out how much they weigh.
Explanation:
in your own words describe the process of a physical change
Answer:
A physical change is when the form of an object changes, but the substance stays the same.
Example: Ice melting into water.
Which characteristic of a substance is considered a chemical property?
its boiling point
its reactivity
its density
its conductivity
Is sulfur dioxide a element?
yes it is a element.
A chemist burns 0.8 g of iron in oxygen.
The iron reacts to form 1.1 g of iron oxide.
Calculate the mass of oxygen that reacted with the iron.
Answer:
0.3g
Explanation:
1.1 - 0.8 = 0.3
Hope this helps
The mass of oxygen that reacted with the iron is 0.3g
The chemist burns 0.8g of iron in oxygen
the iron reacts to form 1.1g of iron oxide
Therefore the mass of oxygen can be calculated by subtracting the mass of iron in oxygen from the mass of iron
= 1.1 - 0.8
= 0.3g
Hence the mass of oxygen that reacted with the iron is 0.3g
Please see the link below for more information
https://brainly.com/question/9631250?referrer=searchResults
what are 2 physical changes in the carbon cycle?
Answer:
Today, the carbon cycle is changing. humans are moving more carbon into the atmosphere from other part of the earth system. more carbon is moving to the atmosphere where fossil fuels, like coal and oil, are burned.more carbon is moving to the atmosphere as you may get rid of forest by burning the tree
Explanation:
hope this give you a hint
calculate the oxidation number of s in S2O8^2-
Given problem:
S₂O₈²⁻
Find the oxidation number of S;
Oxidation number presents the extent of oxidation of each atom of elements a molecular formular or formula unit or an ionic radical.
For radicals:
"the algebraic sum of all the oxidation numbers of all atoms in an ion containing more than one kind of atom is equal to the charge on the ion "
S₂O₈²⁻; oxidation number of O is usually -2
2(S) + 8(-2) = -2
2S - 16 = -2
2S = -2 + 16
2S = 14
S = +7
The oxidation state of S in the radical is +7
How many moles do you have if you have 8.03 x 1023 atoms of oxygen?
Answer:
The answer is 1.33 molesExplanation:
To find the number of moles in a substance given it's number of entities we use the formula
[tex]n = \frac{N}{L} \\ [/tex]
where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
From the question we have
[tex]n = \frac{8.03 \times {10}^{23} }{6.02 \times {10}^{23} } \\ = 1.33388704...[/tex]
We have the final answer as
1.33 molesHope this helps you
Heat rising in a hot-air balloon is an example of __________. conduction convection radiation solar
Answer:Condensation
Explanation:
it
Answer:
convection
Explanation:
I took test I got 100%
What is the process called when the moon bagins to fade from full moon to new moon
Where does the heat that is needed to warm the surface of the ocean come from? A. the Sun B. the Earth's interior C. animals D. the Earth's surface
Answer:
A. The Sun
Explanation:
Answer:
A
Explanation:
Most of our heat source on Earth comes from the Sun.
Explain what happens if you change the number of protons in an element?
Plzzz helpppp!!!
Answer:
When you change the number of protons in an atom, you will change the atom from one element to a different element. Sometimes, when you add a proton to an element, the element will become radioactive. If you change the number of electrons in an atom, you will get an ion of the element.
The equation, reactants
product + thermal energy, describes a(n)_____
reaction.
Answer: Here you go
Explanation:
The general equation for an exothermic reaction is: Reactants → Products + Energy.
All 6 sides of a cube measure 65mm. Calculate the volume of the cube in cm32
Flowering plants are the most successful group of land plants. This is due, in part, to the trait that could be the label for point C. in the cladogram. Consider the organization of the cladogram. What trait, besides flowers, is unique to this group of plants?
Answer:
seeds are protected in fruits in such kind of plants.
Explanation:
The flowering plants are also known as Angiospermae, or Magnoliophyta. Flowering plants are plants that grow flowers. Such plants use seeds to reproduce, or make more plants like them.
Seeds are protected in fruits in such kinds of plants.
Examples of flowering plants are daisies, tulips, oaks, apples.
Answer:
Seeds are protected by a fruit
Explanation:
A train travels at an average speed of 25 miles per hour. How long does it take the train to travel 2000 miles?
nevermind. I was wrong. I didn't see the other answers
the amount of space an object occupies is called its
What kinds of organisms have "naked" DNA?
Answer:
The DNA in prokaryotes is naked DNA.
Explanation:
Prokaryotes have cell walls which are a network of fibres that provides the cell with strength and rigidity. This network in the cell wall allows the cell to be freely permeable. These differ from eukaryotes which have a nucleus containing genetic information (DNA).
Please help me with this question after I have help with my questions i will be giving away 50 points to 4 people to keep on the look out on my page xxx
Answer:
I swear I would help if I knew what the hell was going on on that picture XD
Answer:
D
Explanation:
factors like heat on mcls work on a bell curve, meaning they peak and go down
A black hole is a
a. an object of zero volume and infinite density
b. an object from which nothing, not even light, can escape
c. an object that emits x rays as matter falls into it
d. an object that disappears from our universe
e. all of the above
Answer:
B. an object from which nothing, not even light, can escape
Explanation:
What are the seven most abundant elements?
Answer:
the seven most abundant elements are
oxygen
carbon
hydrogen
nitrogen
calcium
phosphorus
Explanation:
hope this helps
good luck:)
Answer:
oxygen
carbon
hydrogen
nitrogen
calcium
phosphorus