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
Which of the following conclusions can be made about the sedimentary layers?
bed 2 was deposited after bed 3
bed 2 was deposited before bed 3
bed 3 was deposited before bed 1
bed 1 is the youngest
Answer:
I think it's the second one im not sure tho
Hope this helps :)
Write 657000 in scientific notation.
Answer:
600000+50000+7000
Explanation:
pure sodium and chlorine are extremely dangerous, but when combined the result in substance that we use every day. How do you think the properties of sodium and chlorine change when they are combined to make sodium chloride?
Answer:
Explanation:
chlorine has 7 valence electrons while sodium has 1. on their own, they are very reactive elements. a full valence electron shell has 8 electrons, so when elements combine and have 8 electrons in their outer shell, they are not reactive. when sodium and chlorine are combined to form sodium chloride (table salt), it is no longer dangerous. the number of valence electrons changes its reactivity and how it combines.
The properties of sodium and chlorine change when they are combined to make sodium chloride should be explained below.
Information regarding chlorine:chlorine comprises of 7 valence electrons while on other hand, sodium has 1. A full valence electron shell contains the 8 electrons, so when elements combine and have 8 electrons in their outer shell, they are not reactive.
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Convert the following to Celsius
16) 100°K
17) 200°K
18) 273°K
19) 350°K
16) 100- 273= -173°celsius
17) -73°Celsius
18) °Celsius
19) 77°Celsius
What is often added to the water used when reacting the group 1 metals with
water?
Universal indicator
An acid
An alkali
Oil
What is produced when sodium reacts with water?
Sodium oxide and water
Answer:
an acid.
sodium oxide and water
the sum of all the kinetic energies of an object is it's
Answer:
The sum of potential energy and macroscopic kinetic energy is called mechanical energy and stays constant for a system when there are only conservative forces (no non-conservative forces). The more mass a moving object has, the more kinetic energy it will possess at the same speed.
Explanation:
Answer: Mechanical energy
Explanation: The more mass a moving object has, the more kinetic energy it will possess at the same speed
Which of these elements has an electron configuration of [Kr]5s2?
barium
calcium
rubidium
strontium
Strontium has an electron configuration of [Kr]5s²
Further explanationIn an atom there are levels of energy in the shell and sub shell
This energy level is expressed in the form of electron configurations.
Writing electron configurations starts from the lowest to the highest sub-shell energy level. There are 4 sub-shells in the shell of an atom, namely s, p, d and f. The maximum number of electrons for each sub shell is
s: 2 electrons
p: 6 electrons
d: 10 electrons and
f: 14 electrons
From an electron configuration of [Kr]5s² can be concluded :
element is in period 5 (5 = shell)element is group 2(valence electron =2 and block s) has atomic number 38 (Kr = 36 + 2(valence elektron from 5s²)If we look at the periodic system, the elements that meet the requirements in question are Strontium (Sr)
Answer:
D) strontium
11) Identify the number of elements and the number of atoms present in the chemical formula. NaHCO ²
4; 6
5; 6
4,5
3; 5
Answer:
4;6
Explanation:
because there are four elements
Convert the following to Kelvin
12) 0° C
13) -50° C
14) 90° C
15) -20° C
Answer:
12)273.15 kelvin
13)223.15 kelvin
14)363.15 kelvin
15)253.15 kelvin
Explanation:
thank u!!!
Answer:
12) 273.15
13) 223.15
14) 363.15
15) 253.15
Explanation:
Formula:
_C+273.15=_K
_________ change is a change in matter that results in a material changing from one state to another without any change in chemical properties. Example: solid ice changes to liquid water.
Answer:
Physical change
Explanation:
(this is 6th grade science so that’s the closet subject I could find) Do you know an adult who drinks coffee, tea, or soda pop? Think about that person and picture them in your mind. Write a description to help that person understand how they can smell their favorite beverage even though it’s a liquid.
Answer:
Well you could boil the liquid, That would make steam from the liquid. Noramlly you can smell steam.
Explanation:
The hybrid orbitals of a molecule are shown in the figure.
These hybrid orbitals were most likely formed by mixing
one s orbital and one p orbital.
one s orbital and two p orbitals.
one s orbital and three p orbitals.
O two s orbitals and two p orbitals.
Answer:
One s orbital and One p orbital
Explanation:
A. How many molecules of sugar are in 20.5 g of sugar?
Answer:
By definition, one mole (one gram molecular weight) of any substance, contains Avogadro’s number of particles; atoms if you are discussing an element, or molecules if a compound. Avogadro’s number has been determined by several methods, all of the accepted values lie within a range of +-1% about the value of 6.022045 x 10^23/gm. That is a large number, in this case approximately; 602,204,500,000,000,000,000,000 molecules of glucose.
C12H7Cl3FNaO2 what are the elements in that chemical formula
Answer:
hope it helped you
Explanation:
Sodium fluoride - 5-chloro-2-(2,4-dichlorophenoxy)phenol (1:1:1) | C12H7Cl3FNaO2 |
Bromine, a liquid at room temperature, has a boiling point of 58°C and a melting point of –7.2°C. Bromine can be classified as a
compound.
impure substance.
mixture.
pure substance.
Answer:
D. pure substance.
Explanation:
Answer:
:D
Explanation:
List harmful effects of global warming? PLZZ HELP WHOEVER IS FIRST ILL MARK BRAINLEIST
Answer:
first theres the poliution one of the biggest things thats starts global warming then theres recycle and non recycle because people mix there trash up when their not suppossed to.
Explanation:
moles in 9.01x10^23 molecules water
Answer:
The answer is 1.50 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{9.01 \times {10}^{23} }{6.02 \times {10}^{23} } = \frac{9.01}{6.02} \\ = 1.496677740...[/tex]
We have the final answer as
1.50 molesHope this helps you
Answer: 1.50 moles
Explanation:
What form of energy is stored once glucose is from
o A. light energy
O B. kinetic energy
O C. chemical energy
O D. mechanical energy
Answer:
The form of energychemical energy
BRAINLIEST
What type of bond is Cu and F Ionic or Covalent?
- include the process that causes the sun to release so much energy
-The equation for the process that causes the energy. -show what is happening to all the energy coming from the sun.
-how does it affect earth and life on earth
Answer: nuclear fusion, equation:(Z + N) in a nucleus of mass M. The formula is B = (Zmp + Nmn − M)c2, All of the energy from the Sun that reaches the Earth arrives as solar radiation, part of a large collection of energy called the electromagnetic radiation spectrum. Solar radiation includes visible light, ultraviolet light, infrared, radio waves, X-rays, and gamma rays. Radiation is one way to transfer heat.
Explanation: i explained everything in the answer hope this helped
pleaseee help.....ASAP
will mark branliest!!
and give extra points!
Answer:
C
Explanation:
All three can become negative versions: negative ions
Answer:
It is going to be D because Group 1 A and 2 A are s block elements which are METALS, also they are not halogens as the 7 A group is called halogens, Plus they give +1 oxidation state so Correct answer is D as they are group 1 A elements so they have only one valence electron in their valence shell
What mass of the calcium carbonate, to the nearest hundredth of a gram, is decomposed in this reaction.
Answer:
28.00 g is the answer
Answer:200
Explanation:
It’s is the answer
What colors are the fireworks in the photo? How do you
think the matter and energy of fireworks of different colors are similar and
different?
Answer:
Shortly after, the electron will fall back down to a lower energy level, releasing energy in the form of light. Therein lies the key to colorful fireworks!
The matter and energy of fireworks simply rely on the flow of electrons from the ground stage to the excitatory stage.
What is Matter?Matter may be defined as any sort of substance that is constructed of numerous types of particles that occupy physical space and possess inertia. In simple words, matter may be characterized as anything which occupies space and has mass.
When the electrons move from the ground stage to the excitatory stage, they require a significant amount of energy in any form. But when they fall back to the ground stage from the excitatory stage, they liberates energy.
The same principle is applied in the colorful observation of fireworks. The stored energy is released and different colors of fireworks become visible.
Therefore, the matter and energy of fireworks simply rely on the flow of electrons from the ground stage to the excitatory stage and vice-versa.
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Now look closely at the patterns in the table. Compare the elements in each column and row. What can we say about
elements in the same group and elements in the same period of the periodic table?
Select all the correct answers.
The number of electrons in the second energy level increases by one down each column.
Elements in the same row have the same number of occupied energy levels.
For each column, the last occupied energy level has the same number of electrons.
The number of electrons in the first energy level increases by one from Li to Ne.
Answer: Elements in the same row have the same number of occupied energy levels. For each column, the last occupied energy level has the same number of electrons.
Explanation: Straight from PLATO.
On comparing the elements we can say that:
B. Elements in the same row have the same number of occupied energy levels.
Elements in periodic table:
In the periodic table, elements are arranged in an order of increasing atomic number. It comprises of seven periods and eighteen groups.
The elements present in the same row or in the same period will have equal number of energy levels or shells.
Thus, option B is correct.
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what element has 3 valence electrons in the 3rd energy level
Answer:
Aluminum (Al)
Explanation:
It has 3 electron orbitals and has 3 valence electrons
Help fast!
Determine the density of a liquid if it’s mass is 50.5 grams.
Answer:
do we have the volume ?
Explanation:
Do all metals have more electrons than protons
Answer:
no
Explanation:
Human body uses the energy provided from food digestion. Endothermic or exothermic?
Answer:
Endothermic
Explanation:
Exo is outside so exothermic would be outside the body
The carbohydrates are break down into glucose. Then glucose combines with oxygen in the cells and provides energy. Hence, digestion is an exothermic process.
What is an exothermic process ?Food digestion produces heat. This happens as a result of the organism releasing heat during meal digestion. A process that releases heat is exothermic.
Heat is released during an exothermic reaction, raising the temperature of the immediate environment. The environment is cooled through an endothermic process that absorbs heat.
Glucose is created by the breakdown of these carbs. In the cells of our body, this glucose interacts with oxygen to produce energy. So, the process of digesting is exothermic.
Chemical processes involved in food digestion disassemble large food molecules into smaller, more manageable "building block" components.
Thus, Human body uses the energy provided from food digestion is exothermic process.
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How does a rain gauge measure rainfall?
A.
by collecting rain in a measuring container
B.
by counting raindrops
C.
by measuring the sound of rainfall
D.
by measuring the darkness of clouds
Which of the following is a natural source of electricity?
A deep mines
B ligthening
C coal
D car batteries
Answer:
c
Explanation:
by burning it we get steam from.it electricity ..........