all the elements in group 18 are Nobel gases or inert gases . all the elements such as neon , helium, argon etc. ,their outermost shell is completely filled . The noble gases have the largest ionization energies, reflecting their chemical inertness
Calculate the number of protons and neutrons for ²⁴Mg and 88Sr.
Answer:
12 protons and 12 neutrons are present in Mg and
38 protons and 50 neutrons are present in Sr
Explanation:
Answer:
For ²⁴Mg
1. Proton number = 12
2. Neutron number = 12
For ⁸⁸Sr:
1. Proton number = 38
2. Neutron number = 50
Explanation:
For ²⁴Mg:
1. Determination of the number of proton.
The atomic number of an element is simply defined as the number protons in the atom of the element. The atomic number of ²⁴Mg is 12 since no two elements have the same atomic number.
Atomic number = 12
Proton number = Atomic number
Proton number = 12
2. Determination of the Neutron number.
Mass number = 24
Proton number = 12
Neutron number =?
Mass number = Proton + Neutron
24 = 12 + Neutron
Collect like terms
Neutron = 24 – 12
Neutron number = 12
For ⁸⁸Sr:
1. Determination of the number of proton.
The atomic number of ⁸⁸Sr is 38.
Atomic number = 38
Proton number = Atomic number
Proton number = 38
2. Determination of the Neutron number.
Mass number = 88
Proton number = 38
Neutron number =?
Mass number = Proton + Neutron
88 = 38 + Neutron
Collect like terms
Neutron = 88 – 38
Neutron number = 50
It takes 7.21 1019 J of energy to remove an electron from an iron atom. What is the maximum wavelength of light that can do this
Answer:
2.75 × 10^-45 m
Explanation:
From;
E= hc/wavelength
h= Plank's constant= 6.6 × 10^-34 Js
c= speed of light=3× 10^8 ms-1
Wavelength = 6.6 × 10^-34 × 3× 10^8/7.21 × 10^19
Wavelength= 2.75 × 10^-45 m
A molecule contains 24.36 g of nitrogen and 62.64g of sliver
Answer:
This molecule is AgN3
Explanation:
Answer:
AgN3
Explanation:
Mass of nitrogen N is given as 24.36 g
Molar mass of nitrogen N= 14 g/mol.
amount of substance in mol of N = mass/molar mass
=24.36 g/ 14 g/mol.
=1.74 mol.
Given mass of silver= 62,64 g.
Molar mass of silver Ag=107.87 g/mol
Number of mols=62.64 g ÷ 107.87 g/mol.
=0.58 mol.
Ratio of number of mol of N and number of mols of Ag = 1.74 mol / 0.58 mol
=3:1
Hence, empirical formula is AgN₃.
2CuO+2NH3------ 3Cu + 3H2O+ N2. Given that the relative molecular mass of copper oxide is 80, what volume of ammonia is required to completely reduce 120 g of Copper oxide? ( Cu=64, O=16, N=14)
Volume of Ammonia(NH₃) = 22.4 L
Further explanationGiven
Reaction
3CuO+2NH₃⇒ 3Cu + 3H₂O+ N₂
In the problem, the CuO coefficient should be 3 not 2
M CuO = 80
mass CuO = 120 g
Required
The volume of NH₃
Solution
mol CuO :
[tex]\tt mol=\dfrac{mass}{M}\\\\mol=\frac{120}{80}\\\\mol=1.5[/tex]
From the equation, mol ratio CuO : NH₃ = 3 : 2, so mol NH₃=
[tex]\tt \dfrac{2}{3}\times 1.5=1~mol[/tex]
Assume at STP(0 °C, 1 atm) ⇒1 mol = 22.4 L, then volume of NH₃=22.4 L
Methane(CH4) is a gas at room temperature, Methanol (CH3OH) is a liquid. Explain why using types of intermolecular forces present.
Explanation:
Methane is a gas at room temperature but methanol is a liquid because in methane there's London dispersion intermolecular force but in methanol there's H-bond and London dispersion force. H-bond is more stronger than London dispersion force. So, it increases the boiling point of methanol that's why methane is gas at room temperature due to weak attraction of London dispersion force and methanol is liquid.
Methanol has a higher boiling point than methane due to stronger intermolecular forces (IMFs), or attraction between individual molecules. This makes its molecules more difficult to separate, requiring more energy and resulting in a higher boiling point.
What are intermolecular forces?An intermolecular force is a force that mediates the interaction of molecules, including electromagnetic forces of attraction or repulsion that act between atoms and other types of neighboring particles, such as atoms or ions.
Intermolecular forces are classified into five types namely,
Ion-dipole forces.Ion-induced dipole forces.Dipole-dipole forces.Dipole-induced dipole forces.Induced dipole forces.Between ions and polar dipole molecules, ion-dipole forces exist.
Since of stronger intermolecular forces (IMFs), or attraction between individual molecules, methanol has a higher boiling point than methane.
This makes it more difficult to separate its molecules, requiring more energy and resulting in a higher boiling point.
Thus, this is the reason of using types of intermolecular forces present.
For more details regarding intermolecular forces, visit:
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What is the life cycle of an average sized star?
Answer:
The Middle Years
Explanation:
Depending on the size of the star, the period of which thermal energy is created through the process of nuclear fusion can vary. However, for the life cycle of an average star, this can be roughly a few billion to 10 or even 15 billion years
HELPPPPPPPPPP:-( :-( :-( :-(
DETERMINE THE MASS NUMBER OF EACH OF THE ISOTOPES OF LITHIUM
Answer:
6u and 7u
Explanation:
no of neutrons in 1= 3
no of protons in 1=3
mass=3+3=6
same method applies to the 2nd one
SOMEONE HELP ME PLEASE ILL GIVE BRAINLY
HELP IN 8TH GRADE ADV SCIENCE
Answer:
protons: 36
neutrons: 48
electrons: 36
PLEASE HELP !!
Use the diagram below to answer the following questions.
PLEASE HELP
E TE
Figure B
In Figure B, which region contains the noble gas family of elements?
ОА
OD
ОС
OB
Noble gas located in the region D
Further explanationNoble gas are located in group 18 in the periodic table consisting of helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), have a stable electron configuration where the valence electrons are 8(full outer shell of electrons), so it is very hard to react because of its stability
If we look at the periodic system of the elements, the noble gases are on the far right, so that in Figure 8 it is located in area D
And the other region :
A : alkali elements(group 1),
B : alkaline earth elements(group 2)
C : halogen elements(group 17)
When using a light microscope, focus the specimen with the scanning objective
lens first.
Reasoning:
Answer:
The light microscope bends a beam of light at the specimen using a series of lenses to provide a clear image of the specimen to the observer.
According to Le Chatelier's principle, what happens to the equilibrium constant (K) when the concentration of the reactants is doubled? The value of the equilibrium constant (K) is doubled. The value of the equilibrium constant (K) is halved. The value of the equilibrium constant (K) remains the same. The value of the equilibrium constant (K) changes unpredictably.
Answer:
The value of the equilibrium constant (K) remains the same.
Explanation:
A state of dynamic equilibrium is said to have been achieved in a reaction system when the rate of forward reaction equals the rate of reverse reaction.
At equilibrium, doubling the initial concentration of reactants have no effect on the equilibrium constant K. The equilibrium will rather shift to the left or right as required in order to annul the constraint.
Answer:
C
Explanation:
Need help!!! Don’t understand
3. (10 Points) Write a double replacement reaction where one of the products is
copper (11) oxide. Include the states of matter for each of the reactants and
products.
Answer:
Up to now, we have presented chemical reactions as a topic, but we have not ... A single-replacement reaction is a chemical reaction in which one element is ... single-replacement reactions will occur between two given reactants. This is ... Use the activity series to predict the products, if any, of each equation.
Explanation:
SOLVE THIS ASAP!!!!!!!!!
and yes iknow this is not chem don't come at me u_u
EMERGENCY!!! Can someone tell me the answer plz plz I’ll give you brainlist and points plz This is my final test No wrong answers
Answer:
A. the valence electrons
Explanation:
Answer:
The valence electrons
Explanation:
The valence electrons determine an element's properties because chemical properties of each element are determined by the element's electronic configuration and PARTICULARLY by its outermost valence electrons. I hope it helps!
~Good luck
what did bohr consider electrons as?
A. Discrete particles
B. Continuous particles
C. Particles with zero energy
D. None of the above
Answer:
D?
Explanation:
I think D hmm is the answer if I am wrong pls anyone or someone type the right answer but for me is d
Answer:
NOT D!!!!
Explanation:
I am taking the quiz on ck12, it is NOT "none of the above"
What is the rise in sea level between 1930 and 2003?
A)
About 20cm
B)
About 16cm
C
About 12cm
Answer:
about 16
Explanation:
its 20 - ( approximately 5)
= approximately 16
Answer:
It should be (C) about 12cm
i need to know what occupied vs full means for chemistry
What is it called when elements combine to form a chemical compound?
Explanation:
A compound is a unique substance that forms when two or more elements combine chemically.Compounds form as a result of chemical reactions. The elements in compounds are held together by chemical bonds. A chemical bond is a force of attraction between atoms or ions that share or transfer valence electrons.hope it helpful ✌️✌️
Which of these are an atom's valence electrons?
Answer:
The Outer-most Electron shell contains the valence electrons.
Bonus Info:
Valence Electrons are used by atoms to make ionic bonds.
Answer:
Valence electrons are the electrons in the outermost shell, or energy level, of an atom. For example, oxygen has six valence electrons, two in the 2s subshell and four in the 2p subshell. We can write the configuration of oxygen's valence electrons as 2s²2p⁴.
Explanation:
ur welcome
i was doing this in school and i watched a video
23. Soluble salts can be prepared using
the following methods except by
A. action of dilute acids on
metals.
B. action of dilute acid on an
insoluble base.
C. direct combination of
constituent elements.
D. neutralization reactions.
E. precipitation from solutions,
help ple*zzzz*zzz*
Answer:
I think crystallization is a write answer for this question
Explanation:
but according to this (E is the write answer)
An 80 gram sample of a radioisotopes decayed to 40 grams in 3 days how many grams of the original sample would remain after 9 days
Answer: 10 grams
Explanation: Original sample is 80 gram and every three days half of its composition decays so 80 down to 40 in the first 3 days, 20 in the next three days, and 10 in the last three days
What is the molecular formula of the molecule that has an empirical formula of CH2O and a molar mass of 120.12 g/mol
Answer:
C4H8O4
Explanation:
Let (CH20)x
C=1*12.01=12.01 (12.01, 1.01, 16.00 Avg mass of elements)
H=2*1.01=2.01
O=1*16.00=16.00
12.01 + 2.01 + 16.00 = 30.03
120.12/30,03=4
==> (CH2O)4 = C4H8O4
The molecular formula of the molecule that has an empirical formula of [tex]CH_2O[/tex] is equal to [tex]C_4H_8O_4[/tex].
Given the following data:
Empirical formula = [tex]CH_2O[/tex]Molar mass = 120.12 g/mol.Scientific data:
Molar mass of oxygen = 16 g/mol.Molar mass of hydrogen = 1 g/mol.Molar mass of carbon = 12 g/mol.To determine the molecular formula of the molecule that has an empirical formula of [tex]CH_2O[/tex]:
First of all, we would find the molar mass of [tex]CH_2O[/tex]:
[tex]CH_2O =12 +(1\times2)+16\\\\CH_2O =30\;g/mol[/tex]
For molecular formula:
[tex](CH_2O)n = 120.12\\\\30n = 120.12\\\\n=\frac{120.12}{30}[/tex]
n = 4.0
[tex](CH_2O)_4 = C_4H_8O_4[/tex]
Read more: https://brainly.com/question/21280037
"Indicate in each whether the following electron configurations correspond to an atom in its ground state, excited state, or is impossible."
a. [tex]{1s}^{2} {2s}^{2} {2p}^{4} [/tex]
b. [tex] {1s}^{2} {2s}^{2} {2p}^{3} {2d}^{1} [/tex]
c. [tex] {1s}^{2} {2s}^{2} {2p}^{3}{3s}^{1} [/tex]
d. [tex] {1s}^{2} {2s}^{1} {2p}^{2} [/tex]
e. [tex] {1s}^{2} {2s}^{2} {2p}^{1} [/tex]
f. [tex] {1s}^{2} {2s}^{3} [/tex]
Please, I really need help. I don't know what to do...
Answer:
Explanation:
Firstly, let's define what ground and excited state electronic configuration.
Ground state electronic configuration is when the electrons of the atom are in there lowest possible energy level while excited state electronic configuration is when electron(s) have moved to a higher energy level. Examples of these are provided in the options
a. 1s²2s²2p⁴ - This is a ground state electronic configuration (of oxygen) because the electrons are in there lowest possible energy level.
b. This option is not displaying (it is displaying something like an image that isn't loading)
c. 1s²2s²2p³3s¹ - We can see from this that an electron jumped from 2p energy level to 3s (p energy level ought to be completely filled with 6 electrons before another electron moves to the next energy level) meaning the electron is in it's excited state thus this is an excited state electronic configuration (of oxygen).
d. 1s²2s¹2p² - We can see from this also that an electron jumped from the 2s energy level to the 2p energy level (making it 2p² instead of 2p¹ in the ground state). The 2s energy level should ordinarily have 2 electrons. Thus, this is an excited state electronic configuration (of boron).
e. 1s²2s²sp¹ - This is a ground state electronic configuration (of boron) since all the electrons are in there lowest possible energy level.
f. 1s²2s³ - This configuration is impossible because the s energy level should only contain a maximum of 2 electrons, thus impossible to have 3 electrons in the s energy level
Two substances in a mixture differ in density and particle size. theses properties can be used to
Answer:
option 1. Two substances in a mixture differ in density and particle size. These properties can be used to separate the substances. These properties can be manipulated in order to have a better separation between the two substances.
Explanation:
Answer:
Two substances in a mixture differ in density and particle size. These properties can be used to separate both of them using the separating funnel or using filtration (filter paper).
Explanation:
Since their densities are different, one substance should float above the other in the mixture which allows for the separating funnel to let the substance sinking below (with the heavier density) to flow out first before changing the beaker to let the lighter substance flow out.
The substance with a bigger particle size would not be able to pass through the filter paper unlike the substance with the smaller particle size as the filter paper's pores is not big enough for it to pass through, separating both substances (with one on the paper and the other outside the filter paper, preferably in the beaker placed below the paper).
What would happen if a neutron was added to Lithium (7)
Answer:
if you add a neutron to lithium-7 it becomes a compound nucleus of lithium-8
When we drink water, it is absorbed into our blood through the digestive tract. If the concentration of water in body cells is low, cells must get water from the blood. What process allows water to enter body cells from the blood?
Answer:
Osmosis
Explanation:
Water is very essential for the body. When we drink water, our blood cells absorbs water from the body. This happen by a process called as osmosis process. Osmosis is type of diffusion process.
Water along with oxygen and carbon dioxide are some of the simple molecules that moves into the blood cell. Osmosis is the process by which water molecules passes into the cell bodies through its semi permeable membrane.
What is the name given to the group 0 elements
Answer:
the noble gases
Which substance is correctly identified as a homogeneous or heterogeneous mixture?
A. salad -- heterogeneous
B. milk --- heterogeneous
C. river water --- homogeneous
D. beach sand --- homogeneous
Answer:
A
Explanation:
A salad with lettuce, cheese, seeds, tomatoes, broccoli, and other vegetables is an example of a heterogeneous mixture.
Milk is not mixed with anything so that is incorrect
River water is mixed in with dirt and minerals so this one is incorrect
Beach sand is incorrect because you can see colored particles.