Express in scientific notation. Choose the answer with the proper number of significant figures. 9x10^9/4.5x10^1​

Answers

Answer 1

Answer:

Your answer should be 2.4 x 10^9.  please hit the crown

Explanation:


Related Questions

12.
Contrast and compare:
a) ionic and covalent bonding​

Answers

Answer:

Ionic bonds - an intramolecular force exist in a nonmetal and metal compounds such as NaCl. The Na donate 1 electon to Cl to complete its octet rule.

Covalent bond - an intramolecular force exist in a nonmetal and nonmetal compounds such as bonds O2, Cl2, CO2, sugar, proteins and most of organic compounds and biomolecules by sharing electrons to bond.

There are two types of covalent bonds: polar and nonpolar. Polar bond is a bond between two different nonmetal atoms of different electronegativities. While nonpolar bond is a bond between the same atom or two differenct atoms of the same electronegativities (if there is). Their electronegativities pull will cancel so that their overall polarity is zero.

10 g of copper is heated and the mass increases to 12.5 g. What is the mass of the copper in the new substances?

Answers

Answer:

10g

Explanation:

The amount of copper in the heated mass of the new substance produced is still 10g because in any chemical action, mass is always conserved.

According to the law of conservation of matter "matter is neither created nor destroyed in a chemical reaction". The change in mass is only due to oxygen gas that combines with the new copper formed or other substances that joined the mass. The substance will still have the same amount of copper as the original one. Since we started with 10g of copper, we end with 10g of copper.

How much heat is required to raise the temperature of a 6.21 g sample of iron from 25.0 oC to 79.8 oC?

Answers

Answer:

151.1J

Explanation:

Given parameters:

Mass of iron  = 6.21g

Initial temperature of iron  = 25°C

Final temperature of iron  = 79.8°C

Unknown:

Amount of heat = ?

Solution:

The amount of heat require to cause this temperature can be determined using the expression below;

    H  = m c (T₂ - T₁)

H is the amount of heat

m is the mass

c is the specific heat capacity

T is the temperature

    Specific heat capacity of iron 0.444J/g°C

Insert the parameters and solve;

     H  = 6.21 x 0.444 x (79.8 - 25)

     H   = 151.1J

Calculate the percent composition of C6H12O6

Answers

Answer:

Did you just let your cat walk on your keyboard? XD

Could you explain this a bit better please?

I'll answer the question in the replies of this comment if you can give me a bit more information.

Explanation:

May I have brainliest please? :)

Why should a hypothesis be testable?
A. It must be testable in order to be found true or false.
B. It must be testable for the outcome to be predictable.
C. It must be testable for other scientists to consider it reliable.
D. It must be testable if it is to become a scientific theory.

Answers

A. It must be testable in order to be found true or false.

please help me..........​

Answers

Answer:

4/6

6/9

8/12

Explanation:

What is Jadi? is it goat? what language is Jadi?

Under a certain set of conditions, the percent yield of a reaction that produces carbon dioxide is 75.0%. What mass in grams of CO2 will actually be recovered if the theoretical yield is 26.7 grams?

Answers

Answer:

Actual yield = 20.03g

Explanation:

[tex]% yield = 100.\frac{actual yield}{theoretical yield}[/tex]% [tex]yield[/tex] = [tex]100. \frac{actual \ yield}{theoretical \ yield}[/tex]

Actual yield = % yield.(theoretical yield) / 100

Actual yield = 75.26.7/100

Actual yield = 20.025

Answer: I got 20.025 and then I rounded it to 20.0

Explanation:

Which is more electrically negative? 1)C 2)P or 3)S
GUYS PLEASE HELP!!! :((

Answers

Answer:

3 sulphur is more electrically –

When the following equation is balanced, what is the coefficiant for Br?

___I2 +___NaBr rightwards arrow___NaI +_?_Br2

A.
6

B.
3

C.
1

D.
2

1 points

QUESTION 10

The previous question is an example of what type of chemical reaction?

A.
Synthesis

B.
Decomposition

C.
Single Re-Placement

D.
Double Re-Placement

Answers

Answer:

1. A 2. C

Explanation:

because it just is

How did the substance oxygen change the world??

Answers

Answer: The atmosphere of Earth wasn't always full of oxygen. ... An accidental mutation would some day change the world forever as these organisms would become able to feed off of the sunlight around them, and produce oxygen in a process known as photosynthesis. This oxygen, which none of these organisms could use, was toxic.

Please help i will give brainliest

Answers

Question 2 answer is A

Question 4 of 10
What is the molarity of a solution of 3 moles (mol) of FeBr3 in 1/2 L water?
A.
3 mol/2L
B.
2L/3 mol
C.
0.5L/3 mol
D.
3 mol/0.5 L
SUBMIT

Answers

Answer:

B

Explanation:

Answer:

D. 3 mol/0.5 L

Explanation:

Just took the quiz

A bus travels a distance 150km
in 5 hours where as another bus travel 200km in
6 hours which bus travel fast

Answers

Answer: The bus traveling 200km in 6 hours is traveling the fastest.

Explanation:

Bus 1

150km/5hrs

Simplify -> 30km/hr

Bus 2

200km/6hrs

Simplify -> About 33.333km/hr

Which of the following equations is not balanced? ​

Answers

Explanation:

i think the answer is first and last

first equation only.
last one is balanced!!

PLEASE HELP!!!!!!!!
Step 4: Create Lewis dot diagrams.
a) Draw Lewis dot diagrams of the reactants and products on the paper with your chemical equation.
b) Select a different color to use for each element in the chemical reaction. Use your chosen color
for the element’s symbol and for its valence electrons.
c) Label these diagrams “Lewis Dot Diagrams.”

Answers

Answer:

Hey student your question is not proper arrange, i don't understand what you want us to do



2. What properties do all acids have?

3. Why should you never use taste as a method for testing an unknown substance?

4. What is used to detect the presence of acids?

10. What can you use to detect the presence of a base?

11. What are some common bases that we use every day?

12. How does an antacid help reduce heartburn?

13. What happens when acid and base are mixed

14. What is used to determine the pH of a substance?

15. Describe how the pH scale works. In other words, what is it actually measuring?

17. Why is pH important to our environment?

18. Describe how salt is formed.

Pls help!!!!!

Answers

2. They taste sour, are electrolytes, and react with active metals to produce hydrogen.

3. You should NEVER taste unknown chemicals because many are poisonous and can destroy body tissue.

4. Most often dyes are used to detect acids. The dyes will turn a certain color which indicates the presence of an acid.

10. You can use litmus to detect wether a solution is a base or an acid.

11. The most common bases I can think of would be: baking soda, laundry detergent, or soaps.

12. Antacids work by neutralizing the acids in your stomach.

13. When an acid and base are mixed together, they produce a salt.

14. Normally pH meters are used, but you can also calculate the pH using math. (yuck)

15. The pH scale measures how acidic or basic a substance is. It ranges from 0-14, with 7 being neutral.

17. pH is very important to the environment as it helps us measure and monitor for safe water conditions. A rise or fall from the average water pH level can indicate chemical pollution.

18. Salt is formed when an acid and base react with each other. It then has a cation of the base, and anion of the acid.

I hope those helps!! (:

The sum of the protons and neutrons in an atom equals the?
nucleus number
atomic number
atomic mass
mass number

Answers

Answer:

mass number

Explanation:

The sum of the protons and neutrons in an atom equals the mass number of such an atom.

Mass number is the mass of an atom. The mass of an atom is concentrated in the nucleusThe particles in the nucleus are the protons and neutrons.

So;

Mass number = number of protons + number of neutrons.

Write the electron configuration for the electrons identified by the following quantum numbers:

a) 2, 1, 0, -½
b) 4, 2, 0, -½
c) 5, 3, 2, -½

Thanks!

Answers

Answer:

see the answer at the pic

The electron configuration for the electrons as listed are:

a) 1s² 2s² 2p⁵ = 9X

b) 1s² 2s² 2p⁶ 3s²  3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d⁸ = 46 X

c) 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d¹⁰ 6p⁶ 7s² 5f¹⁴

Using the quantum numbers of the identified electrons to derive the electron configuration ( the representation of the distribution of electrons in the orbit of  an atom ) electron configuration of electrons can be calculated using the formula :2n².

where n = orbit number and the various energy levels are represented as 1,2,3,4... while shells of the an atom is written as K,L,M,N

hence the electron configuration of the electrons identified by the quantum numbers are as written above.

Learn more : https://brainly.com/question/20974986

What are the coefficients that will balance the skeleton equation below?

___GaF3 +___KCN rightwards arrow___Ga(CN)3 + ___KF





A.
1, 3, 1, 3

B.
3, 1, 3, 1

C.
1, 1, 1, 3

D.
1, 3, 3, 1

1 points

QUESTION 6

The previous question is an example of what type of chemical equation?

A.
Synthesis

B.
Decomposition

C.
Single Re-Placement

D.
Double Re-Placement

Answers

1, 3, 1, 3

Explanation:

Ga - one on both sides

F - three on both sides

CN - three on both sides

K - three on both sides

But remember that CN was being multiplied by 3 on the right side already, meaning GA(CN)3 didn't mean a coefficient.

Answer:

Double re-placement

The two metals switched dance partners, that means it's a double.

Question 14
1 pts
How many moles of NaCl could be found in 0.4 L of a 0.9 M solution? Round your answer to
two decimal places.

Answers

Answer:

0.36mol

Explanation:

Given parameters:

Volume of NaCl  = 0.4L

Molarity  = 0.9M

Unknown:

Number of moles  = ?

Solution:

To find the number of moles, the molarity of a solution is the amount of solute contained in a solution.

 Molarity  = [tex]\frac{number of moles}{volume}[/tex]  

 Number of moles = molarity x volume

 Insert the parameters and solve;

 Number of moles = 0.4 x 0.9  = 0.36mol

Which models of the atom does the experimental evidence from Bohr's hydrogen experiment support? Explain why these models are compatible with the experimental results.

The models are Daltons, Thompsons, and Rutherfords

Answers

Answer:

Rutherfords

Explanation:

The model of the atom supported by Bohr's hydrogen experiment is the Rutherford's model of the atom.

Rutherford through his experiment on gold foil suggested the atomic model of the atom. The model posits that an atom has a small positively charged center(nucleus) where nearly all the mass is concentrated.

Surrounding the nucleus is the large space containing electrons. In the Bohr's model of the atom, he suggested that the extranuclear space of the atom is made up of electrons in specific spherical orbits around the nucleus.

Benzoic acid, C6H5COOH, is another derivative of benzene. The pH of an aqueous solution of benzoic acid at 298 K is 2.95. Determine the concentration of hydroxide ions in the solution,

Answers

Answer:

[OH⁻] = 8.91x10⁻¹²M

Explanation:

In aqueous solutions, the [OH] and [H⁺] are associated in the equation of hydrolisis of water:

1x10⁻¹⁴ = [OH⁻] [H⁺]

With pH, we can solve for [H⁺] and obtain, the [OH⁻] using this equation:

pH = -log [H⁺]

[H⁺]= 10^-pH

[H⁺] = 1.122x10⁻³M

1x10⁻¹⁴ = [OH⁻] [1.122x10⁻³M]

[OH⁻] = 8.91x10⁻¹²M

SOMEONE HELP ME PLEASE ILL GIVE BRAINLY!

Is the following picture an example of a chemical change or a physical change?

A chemical change, because the atoms are rearranging to form new molecules.

A physical change, because the molecules are staying the same.

A chemical change, because the molecules are staying the same.

A physical change, because the atoms are rearranging to form new molecules.

Answers

Answer:

It would be a physical change, because the atoms are rerranging to form new molecules!

Explanation:

The growth of a plant toward light is called _____.

phototropism
tropism
geotropism

Answers

It's called phototropism

Answer:

The answer is (Phototropism)

Below is a phase diagram for Carbon Dioxide. Use this diagram to answer the following question.
In this example we will start the Carbon Dioxide out at a temperature of -20oC and 1 atm of pressure. If the pressure was raised to 100 atm of pressure while still staying at -20oC, what phases would the Carbon Dioxide change between?

Answers

If you mark those points on the phase diagram it appears to be moving from vapor to liquid. If you can’t see how I determined that please let me know and I can further explain.

Vapor to liquid is the same as saying gas to liquid, which I believe to be the correct answer.

In your own words, please explain how to name acids.

Answers

Answer:

Acids are named based on their anion — the ion attached to the hydrogen. In simple binary acids, one ion is attached to hydrogen. Names for such acids consist of the prefix “hydro-“, the first syllable of the anion, and the suffix “-ic”. Complex acid compounds have oxygen in them.

What causes rain to precipitate from clouds?

Answers

Answer: Precipitation forms in the clouds when water vapor condenses into bigger and bigger droplets of water. When the drops are heavy enough, they fall to the Earth.

Explanation: Have a blessed day!

Answer: Precipitation forms in the clouds when water vapor condenses into bigger and bigger droplets of water. When the drops are heavy enough, they fall to the Earth.

Explanation:hope this helps u

how is a solute and a solvent different

Answers

Solute is substance which is dissolve in a solvent and Solvent is a substance that dissolves solute in a solution.
Answer: Solute is the substance being dissolved, and solvent is the substance that the solute is dissolving in. For example, 1 g of sugar in 100 mL of water. Sugar is being solved so it is the solute, and water is what the sugar is dissolving in so it is the solvent.

PLEASE HELP ME !!!!!!!

Answers

Answer:

it would be 5,045

Explanation:

because it is closer to 5,000. pls correct me if wrong

A wave is a _____that transfers _____ through a ______
A.) medium, disturbance, energy
B.) disturbance, energy, medium
C.) energy, disturbance, medium
D.)disturbance, medium, energy

Answers

The correct answer is B.) disturbance,energy,medium

A wave is a  disturbance that transfers energy through a medium. There

are types of  such as sound and light waves.

A wave involves the transfer of energy such as sound, light waves etc

through a medium. The medium could be through liquids , solids or air and

they have characteristic waves which pass through them.

When a wave transfers energy through a medium, the matter involved

doesn't experience any type of movement.

Read more on https://brainly.com/question/19210453

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