Answer:
d ≈ 0.47
Explanation:
Density is represented by the ratio of mass to volume. We are given the mass (7 grams), but we need the volume.
The volume can be calculated by subtracting the new volume from the old volume.
25 mL - 10 mL = 15 mL
The volume is 15 mL and the mass is 7 grams. Now, set up the ratio. Remember, d = m/v.
d = 7/15
d ≈ 0.47
A student sets up the following equation to convert a measurement. (The stands for a number the student is going to calculate.) Fill in the missing part of this equation. Note: your answer should be in the form of one or more fractions multiplied together.
Answer:
0.090 J/(mmol·°C) × (1000 mmol/mole × 1 kJ/(1000 J)) = 0.090 kJ/mole
Explanation:
The unit of conversion from kilo-Joules to Joules is given as follows;
1000 Joules = 1 kilo-Joule
The unit of conversion from milimoles to moles is given as follows;
1000 milimoles = 1 Mole
Therefore, we have
The value of the given expression is 0.090 J/(mmol·°C) × 1000 mmol/mole × 1 kJ/(1000 J) = 0.090 kJ/mole
0.090 J/milimole = 0.09 kJ/mole.
What three families are found in the center portion of the periodic table
Three families are found in the center portion of the periodic table are of iron, cobalt and nickel atoms.
What are groups in periodic table?Groups are the vertical columns of elements present in the periodic table in which elements of same valency and valence configuration is present.
In the periodic table total 18 groups are present starting from left side to right side. In the middle of the periodic table three families or groups of iron, cobalt and nickel atoms are present which are known by the name of group 8th, 9th and 10th of the periodic table.
So, three families are of iron, cobalt and nickel atoms.
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An atom of which element is represented by the model of a neutral atom? A Carbon (C) B Oxygen (O) C Sulfur (S) D Nitrogen (N) 6. Which of the following describes a proton? I. Has mass II. Has no mass III. Has a positive charge IV. Found in the cloud V. Has a neutral charge A II, IV and V B I, III, IV C II and IV D I and III
Answer:
A. Carbon
B. I, III
Explanation:
Carbon has four valence eletrons meaning that it is more stable than the other choices. A proton has mass and has a positive charge.
Mercury is a liquid metal having a density of 13.6 g/ml. What is the volume of 5.00g of mercury metal
Answer:
The volume of mercury is 0.368mL .
Explanation:
You have to apply Density formula, D = mass/volume. Then, substitute the following values into the formula :
[tex]density = \frac{mass}{volume} [/tex]
[tex]let \: density = 13.6 , mass = 5[/tex]
[tex]13.6 = \frac{5}{vol} [/tex]
[tex]13.6 \times vol = 5[/tex]
[tex]vol = 5 \div 13.6[/tex]
[tex]vol = 0.368ml \: (3sf)[/tex]
Volume of mercury metal of mass 5.00 g and density 13.6 g/ml will be
68 ml.
What is density ?Density of metal can be calculated by mass per unit volume. Density of a substance is directly proportional to mass and inversely proportional with volume.
Density= mass/ volume.
Volume= density * Mass
= 13.6g/ml * 5 g
= 68 ml.
Density of substance is directly proportional with mass and and inversely proportional with volume. If mass of the substance increases density increases, if volume of the substance decreases then density increase.
Therefore, Volume of mercury metal of mass 5.00 g and density 13.6 g/ml will be 68 ml.
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Explain why burning of wood and cutting it into small pieces are considered as two
different types of changes.
Answer:
When wood is burnt , it turns into ashes which is a new substance and process is irreversible one,( chemical change)
When wood is cut into smaller pieces (firewood) this is a physical change
Explanation:
9 x 1025 m
How many significant figures are in
this measurement?
Answer: 9000 - 1 significant figure
Explanation: Since you are multiplying, the number with the least amount of significant figures determines the number of significant figures in the answer. The number 9 has 1 significant figure and 1025 and has 4 significant figures so 9 has the fewest significant figures, meaning your answer will be 1 significant figure.
3
Ethene burns in an excess of oxygen to form carbon dioxide and water.
The equation for the reaction is
C₂H4 & 30₂
2002 + 2H2O.
The relative molecular mass of ethene is 28 and the relative molecular mass of water is 18.
(A: 0, 16; C, 12]
(a) (1) Calculate the relative molecular mass of carbon dioxide.
...[1]
(ii) Complete the following sentences.
28 g of ethene produces ........
..g of carbon dioxide and ..
g of water.
[3]
0.7g of ethene produces ..............g of carbon dioxide.
(b) Complete the diagram to show the bonds in a molecule of ethene.
H
H
C C
H
H
Answer:
(a) (i) 44
(ii) 88 and 36
(iii) 2.2
(b)H₂–C=C–H₂
Will mark you brainliest!
Answer:
D) lithium
Sodium Chloride is salt which is oviously present.
Oxygen is also present because fish use their gills to get oxygen from water.
Plants are present under ocean which release Carbon dioxide.
why do waves refract in shallow water?
Answer:
Refraction of waves involves a change in the direction of waves as they pass from one medium to another,so as water waves are transmitted from deep water into shallow water,the speed decreases,the wavelength decreases and the direction changes
Which of the following is a homogeneous mixture?
a
Mixed cake batter
b
Sand in water
c
Sodium chloride
d
Sulfur
If a question is testable and can provide an answer based on empirical observations and reasonable logic, it can be answered with science.
Answer:
True
Explanation:
Some people argue that a policy of putting out wildfires is having a negative long-term effect on the number and strength of wildfires. Suggest why this could be the case.
Answer:
The answer to this is simple.
There is a school of thought that believes that natural fires are necessary.
Explanation
They are required to reduce the density of the forests that are so thick that when they eventually burn, the effects are usually catastrophic. According to one source, some of these forests are over a hundred years old. When eventually these kinds of forests catch fire, they become very hard to manage and the destruction the leave are usually worse off than if they had not been allowed to so heavy and impenetrable.
Another reason put forward by this school of thought is that the countries who own these forests have politicised wildfires using them as an excuse to attract international funding/assistance because the fires are depleting the worlds protective greenery/earth biggest natural oxygen factory.
Cheers!
— are proteins. a)Skin b)Hydrates c)Skin d)Hides
Answer:
skin
Explanation:
I think its skin because there is a protein that mostly makes up our skin, called keratin.
Another real-world example of a change is rust. Rust is iron oxide (Fe2O3), which results when iron is exposed to oxygen in the air. What are some indicators of rusting? Check all that apply. A) production of light B) color change C) formation of a solid D) formation of a gas
Answer:
c
Explanation:
Answer:
c
Explanation:
An organic chemist measures the temperature T of a solution in a reaction flask. Here is the result. T=35.649C. Convert T to SI units. Round your answer to 3 decimal places.
Answer: 308.649 K
Explanation:
Temperature in Celsius would be converted to Kelvin (K), which is the widely accepted S.I units for measuring Temperature in Chemistry.
Kelvin (K) = 273 + Celcius
= 273 + 35.649 C
= 308.649 K
Chemistry questions below! (●'◡'●)
1. Islands in the middle of the oceans (for example, Great Britain, Hawaii, Bermuda) tend to have more stable climates with smaller temperature fluctuations than regions of the same mass surrounded by land (for example, continents). Use your knowledge of heat energy, specific heat, and heat transfer to explain these facts.
2. Baking soda is sodium bicarbonate (NaHCO3). When you heat baking soda, it breaks down into sodium carbonate powder (Na2CO3), water vapor, and carbon dioxide. The enthalpy of this reaction is 129 kJ. Write a correct thermochemical equation for this reaction, explain how you came up with this equation, and explain what it tells you about the reaction.
(1) Islands are always surrounded by bodies of water, in this case oceans. These islands tend to have more 'stable climates' and 'smaller temperature fluctuations' due to the specific heat of water, which is quite high, 4180 J/kg C. The higher the specific heat, the more the energy needed to raise the temperature of the substance. Land requires less energy to raise it's temperature than water due to it's lower specific heat. Thus, islands tend to have more stable temperatures than regions surrounded by land.
(2) Based on the conditions provided, the thermochemical equation for the reaction should be:
2NaHCO₃ (s) ---> Na₂CO₃ (s) + H₂O (g) + O₂ (g)
This is a decomposition reaction, as it explains that the baking soda breaks down into the products. All we had left to do is balance the equation, adding 2 as the coefficient of the reactant.
(3) Let's rewrite the given equations:
First chemical reaction: H₂(g) + F₂(g) ---> 2HF(g), ΔH₁ = –537 kJ.
Second chemical reaction: C(s) + 2F₂(g) ---> CF₄(g), ΔH₂ = –680 kJ
Third chemical reaction: 2C(s) + 2H₂(g) ---> C₂H₄(g), ΔH₃ = +52.3 kJ.
Fourth chemical reaction: C₂H₄(g) + 6F₂(g) ---> 2CF₄(g) + 4HF(g), ΔH₄ = ?
Now the 'fourth chemical reaction' is the one in which we need to determine the enthalpy:
ΔH₄ = 2(ΔH₁) + 2(ΔH₂) - ΔH₃,
ΔH₄ = 2(–537) + 2(–680) - 52.3 = -2486.3 kJ
How many significant figures does the number have?
9,000,100
Answer:
5 Significant Figures
Explanation:
The type of music represents which variable?
Answer:
can we see the type that is shown?
PLZ HELP!! ILL MARK BRAINLIEST!!! Which would be the most reliable source for information? the Center for Disease Control website Wikipedia, an online publicly edited encyclopedia updates from a Twitter account an editorial on a new drug
Answer:
Center for Disease Control (CDC)
Explanation:
All of the other answers can be changed and may not be backed with actual scientific evidence.
Answer:
CDC
Explanation:
how many significant figures are in 6? thanks!
Answer:
There is only 1 sig figures in 6
Explanation:
There is no 0 after it so it is considered as only 1 significant figure
A substance has a volume of 20 mL and a density of 2.5 g/mL. What is its mass?
Answer:
mass = 50 gExplanation:
Density of a substance can be found by using the formula
[tex]Density(\rho) = \frac{mass}{volume} [/tex]
From the question
Density = 2.5 g/mL
volume = 20 mL
To find the mass substitute the values into the above formula and solve for the mass
That's
Making mass the subject we have
mass = Density × volume
mass = 2.5 × 20
We have the final answer as
mass = 50 gHope this helps you
Answer:
mass=?,volume=20,density=2.5.
density=mass/volume.
which will be 2.5=mass/20
which is mass=2.5×20=50kg
What is the Scientific notation for 8,950,000
**
2. Where are each of the three particles located within the atom?
Answer:
protons and neutrons located within the nucleus, with electrons in orbitals surrounding the nucleus.
I need help with atomic numbers can you please teach me and tell me the answer you will get 10 points
Answer:
[tex]\frac{6}{3} Li^{-}[/tex]
Explanation:
The number of protons and neutrons together create total atomic mass.
The number of protons determine what element it is on the Periodic Table.
The number of electrons v protons determine the charge of the atom.
Protons are positive, electrons are negative, neutrons have no charge.
Since there is 1 more electron than protons, the overall charge is going to be -1.
We are given that there are 3 protons, so that gives us the Lithium element with a -1 charge.
Add up the 3 protons with the 3 neutrons and we get 6 as the total atomic mass in this atom.
When you crush a glow stick and shake it, the two liquids mix and the stick glows. Which statement is true?
Answer:it B,
Explanation: you make two liquids react together. Energy is being given off because light is emitted. The electrons of the liquids must be losing energy in order to produce light.
3.6x = 0.6x + 13 I really need help
Answer: x=13/3
Explanation:
step 1: multiply both sides by 10: 36x=6x+130
step 2: subtract 6x from both sides 30x=130
step 3: divide both sides by 30: x=13/3
what should I choose?
Answer:
the volume of water with egg was 200 and when we removed the egg become 125
Explanation:
200ml - 125ml = 75ml
so 1 millimeter = 1 centimeter cubic
so
75ml = 75 cm3
the answer is 75cm3
What are some examples of Electron?
Answer:
Electrons are the smallest of the particles that make up an atom, and they carry a negative charge. The number of protons and electrons is equal in a neutral atom. The hydrogen atom, for example, has just one electron and one proton. The uranium atom, on the other hand, has 92 protons, and therefore, 92 electrons.
When salt dissolves in water what type of substance is formed
Answer:
homogeneous solution
Explanation:
Hoped that helped :)
Answer:
A mixture
Explanation:
When salt dissolves in water mixture is formed.
It can be separated by evaporating then condensing the water.
Both substances retain their old property.
Hope this helps
Match the following words.
1. A substrate binds to an enzyme at the _______ where the reaction occurs.
2. In a catalyzed reaction, a reactant is often called a __________
3 ________is a measure of how fast an enzyme can convert the reagent to the product.
4. An inorganic substance necessary for the function of some enzymes is called a___________
5. When properly aligned, the enzyme and substrate form an enzyme-substrate (ES) __________
6. A small organic molecule necessary for the function of some enzymes is called a ___________
a. activity
b. cofactor
c. active site
d. substrate
e. complex
f. coenzyme
Answer:
1. active site
2. substrate.
3. activity
4. cofactor
5. complex
6. coenzyme.
Explanation:
1. A substrate binds to an enzyme at the active site where the reaction occurs.
2. In a catalyzed reaction, a reactant is often called a substrate.
3 activity is a measure of how fast an enzyme can convert the reagent to the product.
4. An inorganic substance necessary for the function of some enzymes is called a cofactor.
5. When properly aligned, the enzyme and substrate form an enzyme-substrate (ES) complex.
6. A small organic molecule necessary for the function of some enzymes is called a coenzyme.