Answer:
D
Explanation:
none of these is the answer
Answer: The answer is: D
Explanation: none of these
Hydrogen atoms are excited by a laser to the =4 state and then allowed to emit.
What is the maximum number of distinct emission spectral lines (lines of different wavelengths) that can be observed from this system? Calculate the wavelength of the 4⟶3 transition.
Answer:
1875 nm
Explanation:
Given the Rydberg formula for hydrogen: 1/λ = R(1/n₁² - 1/n₂²)
where R ≈ 1.097* 10^7 /m
Hence;
1/λ = 1.097* 107/m * (1/3² - 1/4²) = 5.3 * 10^5/m
λ = 1.875 * 10-6 m = 1875 nm
8. Describe how crystals of copper sulphate are prepared.
Answer:
Take a cupful of water in a beaker and add a few drops of dilute sulphuric acid. Heat the water. When it starts boiling, add copper sulphate powder slowly while stirring continuously. ... Crystals of copper sulphate will be seen at the bottom of the beaker.
Hope it helps
Why MgO will form after Mg reacting with CuO? (mcq)
Mg forms positive ions and O forms negative ions
Mg is more reactive than Cu
CuO have loose bonding
Answer:
Mg is more reactive than Cu
Explanation:
In the reaction between Mg and CuO to form MgO, MgO will form because Mg is more reactive than Cu.
This kind of reaction is called a single replacement or single displacement reaction.
The replacement of a metallic ion in solution by a metal atom higher in the activity series than the metal in solution falls into this category of reactions. The element Mg is higher than Cu in the activity series. The higher an element is in the activity series, the more reactive they are. Since Mg is more reactive, it will displace the Cu from CuO.i need help please!
asap
Answer:
Earth is pulling up on the book with a force of 4n i think
Explanation:
What is the significance of an electronegativity difference of 1.7 between 2
atoms?
O A. It tells which atoms form positive ions and which atoms form
negative ions.
OB. It represents the boundary between what is considered to be an
ionic or a covalent bond.
C. It determines if the 2 atoms will react to form a molecule.
D. It identifies which metal atoms will join together to form metallic
bonds
Am
B. It represents the boundary between what is considered to be an ionic or a covalent bond.
Further explanationElectronegativity is the ability of atoms to attract electrons, especially in covalent bonds (sharing of electron pairs)
In a periodic system, electronegativity increases in a group, from bottom to top, and in a period from left to right.
From this difference in electronegativity, we can determine the ionic compound, polar or non-polar
Pauling determined the electronegativity scale (based on bond energies), between 0.7 - 4 (Fluorine has the highest number of electronegativities: 4)
Polar covalent compounds have a large electronegativity difference, while nonpolar compounds have a small electronegativity difference.
We can use the difference in electronegativity between the 2 bonded atoms to determine their polarity
<0.5: covalent non polar 0.5- 1.7: covalent polar > 1.7 : ionExample
H₂OH = 2.1
O = 3.5
H₂O = 3.5-2.1 = 1.4 >> polar
O₂= 3.5-3.5 = 0 >> non polar
what happens to the molecules as water freezes PLS HELP THIS IS DO TODAY
During freezing, water molecules lose energy and do not vibrate or move around as vigorously. This allows more stable hydrogen-bonds to form between water molecules, as there is less energy to break the bonds. ... Thus water expands as it freezes, and ice floats atop water.
When water molecule freezes, the water molecules have slowed down enough that their attractions fixed them into fixed positions.
What do you mean by freezing ?The term freezing is defined as a phase transition where a liquid converted into a solid when its temperature is lowered below its freezing point.
The freezing point is the temperature at which a liquid turns solid. In the freezer, for example, water-filled ice cube trays.
Water molecules freeze in a hexagonal pattern, with molecules further apart than when the water was liquid. It is worth noting that the molecules in ice would be vibrating.
Thus, When water freezes, the water molecules slow down to the point where their attractions arrange them into fixed positions.
To learn more about the freezing, follow the link;
https://brainly.com/question/26230908
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What are the benefits and dangers of the Iron element in our daily life?
HELP!!!
write the scientific names of these ionic compounds
Answer:
• Copper chloride
• Copper (II) chloride
• Iron (II) sulfide
• Iron (III) sulfide
Which of the following wave types must have a medium to travel?
A. Ultraviolet light
B. Microwaves
C. Seismic (earthquake) waves
D. Radio waves
E. X rays
Answer:
it is B
Explanation:
Answer: B microwaves
N2+H2》NH3
is it balanced or unbalanced
Please help ASAP 100 points points help I will mark you as brainlister
this is lithium ion with a +1 charge
Refer to your periodic table:
Which of the following has the smallest atomic radius?
Bromine
Astatine
Iodine
Fluorine
iondine
Explanation:
bromine has 185pm, astatine haa 200, iondine has 140 and lastly fluorine has 147. so iondine has the smallest atomic radius
A carpenter uses sandpaper on a piece of wood. Before, the wood felt rough. After, the wood felt smooth. Did the friction between the hand and the wood increase or decrease after using the sandpaper? Describe what the sandpaper did to the wood to make it smoother.
Answer:
Friction between the hand and the wood decreased.
Explanation:
The texture of the wood went from rough → smooth! This means friction between the hand and the wood was notably decreased.
According to this prompt, the carpenter used sandpaper against the wood. Sandpaper just so happens to be a very abrasive substance. The sandpaper polished and leveled out the wood which wore all the jutting bits away.- overall, making it much smoother and more pleasant to touch!
Hope I was of assistance! Have a nice day and Spread the Love! <3
A dull metal object has a density of 8.8 G/ML and a volume of 20 ML calculate the mass
Answer:
Mass = 0.000176 gram
Steps:
m = V × ρ
= 20 milliliter × 8.8 gram/cubic meter
= 2.0E-5 cubic meter × 8.8 gram/cubic meter
= 0.000176 gram
Explanation:
What are natural resources
Answer:
resources that come from the ground or eath naturally which also means that those minerals like coal take hundreds of years to be created
A roller coaster with a mass of 20kg sits at the top of a 30 m high hill. What is the Potential energy of the roller coaster?
(Formula: PE=mgh)
(g= 9.8m/s)
Answer:
The answer is 5880 JExplanation:
The potential energy of a body can be found by using the formula
PE = mgh
where
m is the mass
h is the height
g is the acceleration due to gravity which is 9.8 m/s²
We have
PE = 20 × 30 × 9.8
We have the final answer as
5880 JHope this helps you
Describe the specific steps a scientist would take to solve a particular problem
Answer:
scientific method
Explanation:
- make an observation
- ask a question
- form a hypothesis
- make a prediction based on the hypothesis
- test the prediction
- iterate: use the results to make new hypotheses or predictions
Write the word equations for the following balanced chemical equations.
a. Zn + 2HCl → ZnCl2 + H2
b. 2503 2502 + O2
Answer:
21
Explanation:9+10
Jack has a rock.the rock has a mass of 14g and a volume of 2cm^3.what is the density of the rock?
1
SEE ANSWER
ADD ANSWER
Answer:
7
⋅
g
⋅
c
m
−
3
Explanation:
How many atoms are present in 7.50 mol of chlorine atoms? _
Answer:
4.52 x 10²⁴ atoms Cl
Explanation:
A mole is a name that means a certain number like a dozen means 12. 1 mole of chlorine atoms is 6.022 x 10²³ chlorine atoms. The unit conversion is 6.022 x 10²³/mol.
[tex]7.50molCl*\frac{6.022 x 10^{23} atomsCl}{1molCl} = 4.5165*10^{24} atomsCl[/tex]
Round to 4.52 x 10²⁴ atoms Cl for the correct number significant figures.
WILL MARK BRAINLIEST!!!! HELPPPP
what is the difference between simple distillation and fractional distillation
Answer:
A single distillation cycle is enough to separate the mixture. ... Simple distillation is the method used to separate substances in mixtures with significantly different boiling points, while fractional distillation is used for mixtures containing chemicals with boiling points close to each other.
Explanation:
Your aquarium looks blurred and you wanted to clean it.How will you use recantation technique to separate water from the pebbles and other designs
Answer:
why do you not ask to your maam the answer
what makes a substance a molecule? it’s 7th grade science
Answer:
Molecular substances are made when two or more atoms join together by covalent bonds.
Explanation:
I hope this helps. I took the same class.
A car travels 45 miles per hour. What is this speed in feet per hour?
Answer:
64
hopeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee
compound name of SO2
The transition metals (with the exception of Zn, Cd and Hg) are very much hard and have low volatility. Why Zn ,Cd and Hg has low melting points. (a) These have all their electrons paired. (b) These have maximum number of unpaired electrons. (c) These have very strong metallic bonding. (d) These have more metal-metal bonding.
Answer:
Zn ,Cd and Hg has low melting points because - These have all their electrons paired.
Explanation:
These have all their electrons paired -: All the electrons in the d-subshell are combined with Zn , Cd and Hg. The metallic bonds present in them are, therefore, weak. This is why they have low points of melting and bolting. therefore , this statement is true. These have maximum number of unpaired electrons. Since , these transition metals have all electrons paired , so this statement is incorrect.These have very strong metallic bonding -: Zn, Cd and Hg d-orbital are completely filled. They have poor metallic bonding and less compact packing due to their fully filled d-orbitals, so all of them are volatile in nature. Therefore, this statement is also not valid .These have more metal-metal bonding. -: Since , their metallic bond is weak , so this statement is not true .Hence , the correct option is A (These have all their electrons paired).
What is the effect of tap water, sea water, and rainwater on the rusting rate of iron?
(Please i need an answer π-π)
Answer:
The more acidic the solution the faster it rusts. More Na = more rust
Explanation:
Answer question number 3
Answer:
A
Explanation:
A mixture is formed when two or more substances are physically mixed together. A compound is formed when two or more substances are chemically combined through a chemical reaction.
What is the relationship between the latitude and hours of daylight
Answer:
The tilt of the Earth's axis also defines the length of daylight.Daylight hours are shortest in each hemisphere winter. Between summer and winter
solistice the number of daylight hours decreases and the rate of decrease is larger the higher the latitude.The fewer sunlight hours the colder nights.
Name this element.
i need the answer like now