The model of Neils Bohr postulates that electrons in atoms are found in specific energy levels. Transition from a higher to a lower energy level produces an emission spectrum characteristic of elements.
According to Bohr's model of the atom, an electron in atom exists in distinct energy levels. Electrons can be promoted from lower to higher energy levels when they absorb energy. The electrons are unstable in this higher energy excited state hence they quickly return to the ground state emitting energy. This emission is characteristic of elements.
The following statements are true based on the Bohr model;
Atomic emission spectra are due to electrons losing energy and changing energy levels.Each energy level has a specific energy valueLearn more: https://brainly.com/question/24556237
1 someone help me please
Answer:
J
Explanation:
Because the vapor can be turned back to water and the vapor is still considered water.
is mixing acid and base a chemical change or a physical change
Answer : chemical reaction
Mixing an acid with a base is a common chemical reaction.
Answer:
It is a chemical reaction.
Explanation:
Mixing acid and base is a common chemical reaction.
(I had my answer in the comments bc at the time I couldn't submit it as a answer so here ya go)
Hope this helps! :)
how many molecules of oxygen are needed to make 3.5 oxygens of water?
Answer:
57.6g
Explanation:
So, if in one mole of water, 16 g of oxygen atom is present. Then, in 3.6 moles of water, the mass of oxygen present will be 3.6×16=57.6g. Therefore, the amount of oxygen present in 3.6 g water is option (B)- 57.6 g.
lactase is an enzyme that breaks down a sugar found in dairy products known as lactose. Some people are lactose intolerant, and this can be due to not having enough lactase production. People who are lactose intolerant may not feel well after eating foods containing lactose. Illustrate the scenario and describe the relationship between the substrate and enzyme.
Answer
If people with lactose intolerance eat dairy products, the lactose from these foods pass into their intestines, which can lead to gas, cramps, a bloated feeling, and diarrhea.
Some people can have small amounts of dairy without problems. Others have a lot of stomach trouble and need to avoid all dairy products. Many foods, drinks, and digestive aids are available to help manage lactose intolerance.
Explanation:
What happens if an atom has a different amount of electrons than protons? (Select all that apply) A: The particle is no longer an atom. B: The particle becomes a different element. C: The particle has a charge. D: The particle is considered an ion.
What will happen in a case there is different number of electrons compare to protons is D: The particle is considered an ion.
An ion can be regarded as atom or molecule which posses some amount of electron more than amount of protons and vice versa. It can be regarded as molecules that has a charge. i.e ( -ve or +ve)When the number of electron in this molecules or atom is more that that of the present protons, then the ion is negatively charged ion.When a particles posses less electron compare to the present protons then the ion is positively charged.
Therefore, an ion can be charged positively and it can be charged negatively
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6. Which of the following statements is/are TRUE of metals and non-metals?
l. Non-metals are heat conductors.
ll.Aluminum, copper and iron are non-metals.
III. Phosphorus and sulfur are poor conductors of heat and electricity
IV. Metals have luster.
A. I only
B. III only
C. III and IV
D. I and II
Answer:
I= true
III=false
iv=true
15.3 Determine the mass of the following: 15.3.1. 2 mol calcium atoms
15.3.2. 0,3 mol nitrogen molecules
15.3.3. 0,5 mol table salt
15.3.4. 0,2 mol hydrochloric acid
15.3.5. 0,08 mol sodium carbonate (Na2CO3)
15.3.6. 0,25 mol ammonium sulphate (NH4)2SO4
Answer:
hh
Explanation:
The RDI for sodium for adults is 2300mg. What amount of table salt (in grams) contains this quantity of sodium? Express answer to two significant figures and include the appropriate units.
The amount of table salt (in grams) contains this quantity of sodium is 5.844 g.
What is table salt?Table salt is made up of sodium and chloride. The chemical formula of table salt is NaCl. This is a common salt used daily in the kitchen. This gives us a taste of food. And it is also necessary for the body.
The RDI for sodium for adults is given that is 2300 mg. The quantity of sodium is given = 2300 mg = 2.30 g (since the answer is asked in grams)
As we know, table salt is NaCl.
The molar mass of table salt (NaCl) is 58.44 g/mol
The molar mass of sodium (Na) is 23.00 g/mol
So, for 23.00 g sodium, we need 58.44 g NaCl.
And, for 2.30 g sodium we require (58.44 g x 2.3 g) / 23 g = 5.844 g = 6 g (to one significant figure).
Therefore, the amount of sodium is present in 5.844 grams of table salt.
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List two differences between a map and a giobe
Answer:
1. A map is two dimensional, while a globe is three dimensional
2. A globe is a scaled down representation of the entire Planet Earth. A map can represent an area of any size.
Explanation:
1. A map is usually a sheet of rectangular paper that is a flattened image of an area as seen from the top. A globe on the other hand is a sphere which is a 3D shape.
2. Earth is in the shape of a sphere, so Globes are a smaller representation of the planet. A map can be for a city, state, country, or the world.
Tom tells Greta that his father, an astronomer, is planning a scientific experiment to study another galaxy. Using a powerful telescope, Tom's father will record data of shifts in light patterns and track their different sources every 30 seconds. He will later study the data. Greta says that this is not an experiment. Which of these reasons supports Greta's statement?
It is not performed in a lab.
There are too many variables.
It does not have a control group.
It uses only theoretical predictions.
Answer:
it does not have a control group
Americans drink 5,604,000 gallons of sweet tea each day. How many liters is
that? (1 gal = 3.79 L)
5604000gallon =21239160 liters
Draw a Lewis structure for the following molecules on scratch paper. Then give the number of bonds between the C and N in each.
CH5N
CH3N
HCN
Refer to the attachments
Look at the graph above showing the composition of air. Which component is the solvent?
The component that would be the solvent from the graph would be nitrogen.
From the graph, nitrogen takes up 78%, oxygen had 21%, while the remaining gases take the remaining 1%.
A solvent is a substance or the component of a solution that has the capacity to dissolve other substances
In a mixture consisting of 2 or more substances, the substance with the highest volume usually acts as the solvent.
In this case, nitrogen holds the highest volume of all the gases in the graph. Thus, it can be considered as the solvent while the remaining gases are the solutes.
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Hello there
i am looking for some quick help on this question thank you.
Liquid B has a mass of 75 g and a volume of 25 ml. What is liquid B's density?
1: .33 g/ml
2: 3 g/ml
3: 75 g
4: 25 ml
Answer:
To measure the density of a liquid you do the same thing you would for a solid. Mass the fluid, find its volume, and divide mass by volume. To mass the fluid, weigh it in a container, pour it out, weigh the empty container, and subtract the mass of the empty container from the full container.
Explanation:
Answer:
[tex] \rho = \frac{mass}{vol} \\ = \frac{75 \: g}{25 \: ml} = 3g .{ml}^{ - 1} [/tex]
is mercury homogeneous or heterogeneous?
Answer:
homogenous
Explanation:
its a pure element, so it is a pure substance
If an ionic compound has a 2- charge how does that affect the total number of electrons in a Lewis structure
In the situation where an ion has a charge of -2, the Lewis structure is affected because it must add two additional electrons.
The Lewis structure is a term to refer to the graphical representation that shows the pairs of electrons in dashes or points of bonds between:
The atoms of a moleculeThe lone electron pairs that may existAdditionally, the charge of an ionic compound is calculated using the difference in electrical charge between the electrons. On the other hand, an ion is formed by adding or removing electrons, so the magnitude of the resulting charge depends on the number of electrons added or removed.
According to the above, if an ionic compound has a -2 charge, the Lewis structure must add two electrons.
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Which statement is true about a neutral solution?
Its pH is less than 7.
Its pH is greater than 7.
It has the same concentration of hydronium and hydroxide ions.
It has a greater concentration of hydroxide ions than hydronium ions.
Answer:
C. It has the same concentration of hydronium and hydroxide ions.
Explanation:
A neutral solution means that it's a balanced substance that is neither a base nor an acid. For example, pure water is a neutral substance.
(I also did the test for this and I got it correct.)
Hope this helps any future people doing this! :)
Answer:same concentration of hydronium and hydroxide ions (C)
Explanation:
which is a semi conductor? metal, nonmetal, mettaliod
Answer:
mettaliod
Explanation:
Answer:
Metalloids have properties intermediate between the metals and nonmetals. They can form alloys with other metals. … Some metalloids, such as silicon and germanium, can act as electrical conductors under the right conditions, thus they are called semiconductors.
Explanation:
Mark me as the brainlyest
Help again thank you lots of points for you keep helping I will give you a good review thanks!
Answer:
it would prob be planet y
If the reaction occurs between Fe2S3(s) and H(aq) and the equation is properly balanced with the
smallest whole-number coefficients, what is the sum of the coefficients for all reactants and products?
Fe2S3(s) + H+ (aq)
Please answer this mathematically.
In the reaction between Fe₂S₃(s) and HBr(aq), the sum of the coefficients for all reactants and products is 12.
If the reaction occurs between Fe₂S₃(s) and HBr(aq) and the equation is properly balanced with the smallest whole-number coefficients, what is the sum of the coefficients for all reactants and products?
Let's consider the unbalanced equation for the reaction between Fe₂S₃(s) and HBr(aq). This is a double displacement reaction.
Fe₂S₃(s) + HBr(aq) ⇒ FeBr₃(aq) + H₂S(g)
We will balance it using the trial and error method.
First, we will balance Fe atoms by multiplying FeBr₃ by 2.
Fe₂S₃(s) + HBr(aq) ⇒ 2 FeBr₃(aq) + H₂S(g)
Then, we will balance S atoms by multiplying H₂S by 3.
Fe₂S₃(s) + HBr(aq) ⇒ 2 FeBr₃(aq) + 3 H₂S(g)
Finally, we will get the balanced equation by multiplying HBr by 6.
Fe₂S₃(s) + 6 HBr(aq) ⇒ 2 FeBr₃(aq) + 3 H₂S(g)
The sum of the coefficients for all reactants and products is:
[tex]1 + 6 + 2 +3 = 12[/tex]
In the reaction between Fe₂S₃(s) and HBr(aq), the sum of the coefficients for all reactants and products is 12.
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Explain the following: Unless the loss of reactant is extreme, only the loss of limiting reactant mass truly introduces error into your theoretical yield calculation.
The scientific community dismissed John Needham’s attempt to prove spontaneous generation. What was the reason that they gave? *
A. By sealing off the flask he deprived the environment of air, a requirement of spontaneous generation
B. He used the wrong type of flask
C. He left the flasks open to the air for too long
D. He did not boil his broth long enough and the flasks were not cleaned prior to the experimenter.
Answer:
He did not boil his broth long enough and the flasks were not cleaned prior to the experimenter
why do ionic compound form crystals ?
Answer:
Ions bound together by electrostatic attraction form ionic crystals.Stability of ionic solids depends on lattice energy, which us released in the form of heat when two ions are brought together to form a solid. Lattice energy is the sum of all the interactions within the crystal.when particles of unreactive .... collide, they bounce off each other at high speed without any loss of energy. What word is supposed to be filled in on the dots?
Answer:
Groups
Explanation:
The groups determine if the atom is reactive or not, take the Noble Gases for example, they are very very very unreactive.
Why is land more vulnerable to wind erosion during droughts?
A: Excessive rainfall causes soil to erode.
B: Plants that hold the soil die off.
C: High temperatures dry out the soil.
D: Cold temperatures cause soil to freeze.
The mass of 1 mole of phosphorus atoms is how many
grams.
Answer:
approximately 30 g.
The mass of 1 mole of phosphorus atoms is approximately 30 g.
Explanation:
Hope this helps.
Which two substances are among the four major types of organic
compounds made by living things?
A. Potassium
B. Water
C. Carbohydrates
D. Proteins
Answer: Carbs and proteins
Explanation:
Answer:
the answer is proteins
Explanation:
did the problem
Alkali metals react violently with water. How much Hydrogen gas (in g) is produced when 10.0 g of sodium reacts with excess water according to the following equation?
2Na + 2H2O ----> 2NaOH + H2
The mass of Hydrogen gas produced when 10.0 g of sodium reacts with excess water is 0.44 g.
From the question,
We are to determine the mass of Hydrogen gas produced when 10.0g of sodium reacts with excess water.
From the balanced chemical equation for the reaction
2Na + 2H₂O → 2NaOH + H₂
This means
2 moles of sodium reacts with 2 moles of water to produce 2 moles of sodium hydroxide (NaOH) and 1 mole of Hydrogen gas.
Now, we will determine the number of moles of sodium present
Mass of sodium = 10.0 g
Atomic mass of sodium = 22.99 g/mol
From the formula
[tex]Number\ of\ moles\ = \frac{Mass}{Molar\ mass}[/tex]
∴ Number of moles of sodium present = [tex]\frac{10.0}{22.99}[/tex]
Number of moles of sodium present = 0.43497 mole
From the balanced chemical equation
2 moles of sodium reacts with 2 moles of water to produce 1 mole of Hydrogen gas.
Then,
0.43497 mole of sodium will react with 0.43497 mole of water to produce [tex]\frac{0.43497}{2}[/tex] mole of Hydrogen gas
[tex]\frac{0.43497}{2} = 0.217485[/tex]
∴ 0.217485 mole of Hydrogen gas was produced during the reaction
Now, for the mass of Hydrogen gas produced
Using the formula
Mass = Number of moles × Molar mass
Molar mass of H₂ = 2.016 g/mol
∴ Mass of Hydrogen gas produced = 0.217485 × 2.016
Mass of Hydrogen gas produced = 0.43845 g
Mass of Hydrogen gas produced ≅ 0.44 g
Hence, the mass of Hydrogen gas produced when 10.0 g of sodium reacts with excess water is 0.44 g.
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is distilled water a pure substance or mixture
Answer:
pure substance,...................
In which of Earth's layers are the convection currents?
crust
mantle
inner core
lithosphere
