Please help..
Describe how to perform a three step 1:100 serial dilution of 10μlof a bacterial culture.

Answers

Answer 1

Answer:

For a 1:100 dilution, one part of the solution is mixed with 99 parts new solvent. Mixing 100 µL of a stock solution with 900 µL of water makes a 1:10 dilution. The final volume of the diluted sample is 1000 µL (1 mL), and the concentration is 1/10 that of the original solution

Explanation:

i hope that gives you an idea


Related Questions

Please help me with this.

Answers

Answer:

its should be rises

Explanation:

Answer:

its rises I'm pretty sure

Explanation:

iwhen warm air rises it expands and when air expands it becomes less dense (or of low pressure)

is bird seed homogeneous or heterogeneous

Answers

Answer:

heterogeneous          

In order to give birds a varied and balanced diet, commercial bird seed blends typically include a range of seeds, grains, and other substances. As a result, bird seed is frequently categorised as a heterogeneous blend.

A seed is referred to as homogenous if its genetic makeup, size, shape, and other traits are all consistent. To guarantee consistency in the ensuing plants, these seeds are typically created through controlled breeding or genetic manipulation. A heterogeneous seed, on the other hand, is one that varies in genetic makeup, size, shape, and attributes. These seeds frequently result from cross-pollination or natural pollination between various species or kinds.

To know more about heterogeneous seed, here:

https://brainly.com/question/30583932

#SPJ6

1. What is the atomic mass of hydrogen if 99.985% is hydrogen-1 and 0.015% is hydrogen-2?​

Answers

The atomic mass of Hydrogen : 1.02985

Further explanation  

Isotopes are elements that have the same Atomic Number (Proton)  

Atomic mass is the average atomic mass of all its isotopes  

In determining the mass of an atom, as a standard is the mass of 1 carbon-12 atom whose mass is 12 amu  

An atomic mass unit = amu is a relative atomic mass of 1/12 the mass of an atom of carbon-12.  

Mass atom X = mass isotope 1 . % + mass isotope 2.% ..

99.985% is hydrogen-1 and 0.015% is hydrogen-2

The atomic mass of Hydrogen :

[tex]\tt atomic~mass~H=0.99985\times 1+0.015\times 2\\\\atomic~mass~H=1.02985[/tex]

Two seventh grade students are studying how sound waves are transferring energy.
They beat a pot and the sound waves cause waves in the glass of water.
How would the students increase the amplitude of the waves in the glass of water?
Hit the pot softer with less energy
Hit the pot harder with more energy
Hit the pot faster at a higher frequency
Hit the pot faster at a slower frequency

Answers

Answer:

Hit the pot faster at a higher frequency

Explanation:

I feel like it would be because it makes more sense to me but I really have no clue tbh

How do you know something is there if you can't see it?

Answers

Answer:

Explanation:

Use your other senses such as touch or smell, does it react in different temperatures, is it then visible under a microscope, does it react with different elements or gases?   Think outside the box.

Answer:

we know that someone or something is near us even when we cant see it you see our self conscious minds can pick up on the slightest detail even when we dont pick up on it also you can  thank the six senses as well for why we can tell something or someone is there

Explanation: i watch criminal minds and pay attention to the random facts spencer reid spits out

can I get help please​

Answers

yes ofc! just simply show us the question and we will answer it

Which of the following traits are inherited from parents when the genetic material found in genes is passed to offspring on the chromosomes located in egg and sperm?


A. Sharp Teeth
B. Penguins caring for young
C. All the above
D. Flower color

Answers

I believe it is B. I’m sorry if i’m wrong. Tell me if i’m wrong or right!

Please answer correctly !!!!!!!!!!!!!!! Will mark brainliest !!!!!!!!!!!!!!!!!!!!

Answers

Answer:

i dont have an answer for sure because it doesnt specify WHAT its energy chang occurs but i think its physical change

Explanation:

Physical changes only change the appearance of a substance, not its chemical composition. Chemical changes cause a substance to change into an entirely substance with a new chemical formula. Chemical changes are also known as chemical reactions.

examples of chemical change:

burning a fire

boiling an egg

digestion

examples of physical change:

melting ice

rusting

breaking a pencil

hope i helped!!

*please be serious *
What is one way active transport is different from diffusion ?

Answers

Answer:

Explanation:

During active transport, molecules move from an area of low concentration to an area of high concentration. This is the opposite of diffusion, and these molecules are said to flow against their concentration gradient.

You mix 15g of water with 10 grams of sodium chloride. After the reaction occurs, how
many grams of your new substance do you have?

A) 15g
B) 25g
C) 20g
D) not enough information

Answers

Answer:

B) 25g

Explanation:

Every reaction must follow the law of conservation of mass.

Law of conservation of mass:

According to the law of conservation mass, mass can neither be created nor destroyed in a chemical equation.

Explanation:

This law was given by French chemist  Antoine Lavoisier in 1789. According to this law mass of reactant and mass of product must be equal, because masses are not created or destroyed in a chemical reaction.

For example:

In given photosynthesis reaction:

6CO₂ + 6H₂O + energy → C₆H₁₂O₆ + 6O₂

there are six carbon atoms, eighteen oxygen atoms and twelve hydrogen atoms on the both side of equation so this reaction followed the law of conservation of mass.

In given example:

Water + sodium chloride   →   Product

15 g   +      10 gram       =              25 g

25 g           =      25 g

What are the names of all of the valves in the
heart? Check all that apply
ventricular valve
aortic valve
atrium valve
carotid valve
mitral valve
pulmonary valve
tricuspid valve

Answers

tricuspid valve: located between the right atrium and the right ventricle.
pulmonary valve: located between the right ventricle and the pulmonary artery.
mitral valve: located between the left atrium and the left ventricle.
aortic valve: located between the left ventricle and the aorta.

What is the amount of water vapor in the air called?

relative humidity

humidity

dew point

freezing point

Answers

Answer:

relative humidity

Explanation:

1. The ability to reflect light; shininess
ductility
O luster
o conductivity
o malleablity

Answers

Answer:

Luster

Explanation:

I can not really explain

-the metallic substance

luster haha i’m learning this in my science class but you can google it to check

8. If a sample of chloroform is initially at 25°C, what is its final temperature if 150.0 g of chloroform
absorbs 1.0 kilojoules of heat, and the specific heat of chloroform is 00.96 J/gºC?

Answers

Answer:

The final temperature is 31.95° C.

Explanation:

Given that,

Initial temperature of a sample of chloroform, [tex]T_i=25^{\circ} C[/tex]

Mass of chloroform, m = 150 g

It absorbs 1 kJ of heat, Q = 10³ J

The specific heat of chloroform, c = 00.96 J/gºC

We need to find the final temperature. The heat absorbed by an object in terms of specific heat is given by :

[tex]Q=mc\Delta T\\\\Q=mc(T_f-T_i)\\\\\dfrac{Q}{mc}+T_i=T_f\\\\T_f=\dfrac{10^3}{150\times 0.96}+25\\\\=31.95^{\circ} C[/tex]

So, the final temperature is 31.95° C.

Carbon is stored in leaves in various forms, such as sugar. When leaves decay,they lose mass. Which of the following sentences explains what happens to the carbon that is stored in leaves when they decay? * 1 point

Answers

Answer:

This question lacks options, however, it can be answered based in general understanding. The answer is:

The carbon is released into the atmosphere and soil during decomposition

Explanation:

Carbon is an important element that makes up the biomass of living organisms. Organisms like plants as described in this question, store carbon as sugars, which they synthesized during photosynthesis. However, when they decompose/decay, they lose this carbon content.

Decomposition is the process carried out by microbes such as fungi, bacteria etc involving the breaking down of an organic molecule into inorganic ones. Hence, when leaves of a plant die, they undergo decomposition i.e. the carbon content in their leaves present as sugar (organic molecules) is broken down to release the carbon in form of carbon dioxide, into the atmosphere, soil etc. Hence, the carbon that is stored in leaves are RELEASED when they decay causing them to lose mass.

Provide background information about different types of chemical reactions.
Synthesis Reactions
Decomposition Reactions
Single Replacement Reaction
Double Replacement Reaction
Combustion
Then explain, in a general sense, how you will determine which of the above types of reactions are occurring in your experiments.

Answers

Answer:

.

Explanation:

-Synthesis reactions are reactions that appear when two distinct atoms or molecules engage to structure a specific molecule or compound. Most of the time, when a synthesis response occurs, electricity is launched and the response is exothermic. However, an endothermic consequence is additionally possible.

-A decomposition response starts offevolved from a single substance and produces extra than one substance; that is, it decomposes. One substance as a reactant and greater than one substance as the merchandise is the key attribute of a decomposition reaction. For example, in the decomposition of sodium hydrogen carbonate (also recognized as sodium bicarbonate)

-A single-replacement response (sometimes referred to as a single-displacement reaction) is a chemical response in which one aspect is substituted for every other factor in a compound, producing a new aspect and a new compound as merchandise

-A double-replacement response (sometimes referred to as a double-displacement reaction) takes place when components of two ionic compounds are exchanged, making two new compounds. A attribute of a double-replacement equation is that there are two compounds as reactants and two distinctive compounds as product

-A combustion response happens when a reactant combines with oxygen, many instances from the atmosphere, to produce oxides of all different factors as products; any nitrogen in the reactant is transformed to elemental nitrogen, N2. Many reactants, referred to as fuels, incorporate normally carbon and hydrogen atoms, reacting with oxygen to produce CO2 and H2O

A chemical reaction may involve one or more reactants to yiled one or more products.

Types of reactions

Below we are going to discuss the types of reaction under the following headings;

Synthesis reaction - This is a reaction in which two or more substances come together to yiled a single product.

Decomposition reaction - This involves the breakdown of a substance into new substances.

Single Replacement Reaction- This is a type of reaction in which an atoms replaces another in a compound.

Double Replacement Reaction - This is a reaction in which cations exchange anion partners in a reaction

Combustion - This is a reaction in which a substance is burnt in oxygen.

Learn more about reactions:https://brainly.com/question/17434463?

#SPJ2

Answer fast please What system is the heart part of
A. Circulatory
B. Respiratory
C. Digestive
D. Skeletal

Answers

The heart is a part of the Circulatory system.

Answer:

A. Circulatory System

*WILL GIVE A BRAINIEST & 15 POINTS TO THE CORRECT ANSWER*

When an electron falls back to its original shell, the electron will...

A.) absorb energy as it goes to the excited state
B.) absorb energy as it goes to the ground state
C.) release energy as it goes to the excited state
D.) release energy as it goes to the ground state

Answers

Answer: D

Explanation:

i need help ASAP plz its timed

Answers

Answer:

B) iron (Fe) im sure its iron

Please answer correctly !!!!! Will mark brainliest !!!!!!!!!!!!!!

Answers

Answer: Solids

Explanation:

In the solid state, the individual particles of a substance are in fixed positions with respect to each other because there is not enough thermal energy to overcome the intermolecular interactions between the particles. As a result, solids have a definite shape and volume.

What is the different between stereotyping someone and judging them? paragraph in length please

Answers

Answer:

Stereotyping provides humans with the ability to quickly sort out patterns in a randomly diverse world filled with people of every size, shape, gender, age, color, and sexual orientation. And it’s just a quick first pass, nothing more

Which sentence best explains the relationship between pressure and the
solubility of a gas?
A. The greater the pressure, the more gas that will dissolve.
B. Solubility increases with pressure for some gases but not others.
C. The lower the pressure, the more gas that will dissolve.
D. Pressure has no effect on the solubility of gases.

Answers

Answer: A. The greater the pressure, the more of gas that will dissolve.

Explanation: Increasing pressure increases the solubility of gases. It has little effect on the solubility of liquids and solids.

Gina summarizes the ideas that led to the current atomic model.
1. Dalton developed the theory that all matter is made of atoms.
2. Thomson discovered that atoms contain electrons.
3. Rutherford discovered that atoms have a nucleus.
4. Schrödinger developed the electron cloud model.
5. Bohr developed the model in which electrons orbit the nucleus.

Which change should Gina apply to correct the summary?
Switch 1 and 5.
Switch 2 and 3.
Switch 4 and 5.
Switch 3 and 1.

Answers

Answer:

C.   Switch 4 and 5

Explanation:

edge2021

The atomic model gives a detailed understanding of the atoms and the sub-atomic particles. The models were given in order by Dalton, Thomson, Rutherford, Bohr, and Schrödinger. Thus, option C is correct.

What is the atomic model?

The atomic model is the representation of the atom of the element along with the sub-atomic particles. The first model was given by Dalton, which stated that matter is composed of atoms.

Later Thomson discovered the presence of the electron present in the sea of the positive charges. In addition, Rutherford gave the presence of the positive nucleus in the middle of the atom.

Bohr's model gave the presence of the electron in the orbit of the atom around the nucleus. At last, the current atomic model was given by Schrödinger and is known as the electron cloud model.

Therefore, option C. Gina should Switch 4 (Schrödinger' model) with model 5 ( Bohr 's model).

Learn more about atomic models here:

https://brainly.com/question/11311946

#SPJ2

whats the formula for density

Answers

p =[tex]\frac{m}{V}[/tex]

p equals m over V

hope this helps!!

P = density

m = mas

V     =     volume

Explanation:

easy

A cylinder, with a piston pressing down with a constant pressure, is filled with 2.10 moles of a gas (n1), and its volume is 46.0 L (V1). If 0.700 mole of gas leak out, and the pressure and temperature remain the same, what is the final volume of the gas inside the cylinder?

Answers

Answer:

The volume is  [tex]V_2 =15.33 \ L[/tex]

Explanation:

From the question we are told that

    The number of moles of the gas is  [tex]n_1 = 2.10 \ moles[/tex]

      The volume of the gas is  [tex]V = 46.0 \ L[/tex]

        The  of moles of the gas that leaked is  [tex]n_2 = 0.700 \ mol[/tex]

Generally from the ideal gas law

      [tex]PV = nRT[/tex]        

Generally at constant pressure and temperature

        [tex]\frac{V}{n} = constant[/tex]

So   [tex]\frac{V_1 }{n_1} = \frac{V_2 }{n_2}[/tex]

=>    [tex]V_2 = \frac{ V_1 * n_2 }{ n_1}[/tex]

=>    [tex]V_2 = \frac{ 46.0 * 0.700 }{ 2.10 }[/tex]  

=>    [tex]V_2 =15.33 \ L[/tex]

             

     


how many atoms are in a sample of uranium with a mass of 789 g.

Answers

Number of atoms : 1.996 x 10²⁴

Further explanation  

The mole is the number of particles(molecules, atoms, ions) contained in a substance  

1 mol = 6.02.10²³ particles

Can be formulated

N=n x No

N = number of particles

n = mol

No = Avogadro's = 6.02.10²³

mol of Uranium with mass=789 g (Ar U=238,02891 u) :

[tex]\tt mol=\dfrac{mass}{Ar}\\\\mol=\dfrac{789}{238,02891 u}\\\\mol=3.315[/tex]

Number of atoms :

[tex]\tt N=3.315\times 6.02\times 10^{23}\\\\N=1.996\times 10^{24}~atoms[/tex]

How many moles of manganese in 4.07 x 1024 atoms of manganese?

Answers

Answer:

6.76 moles

Explanation:

To find the number of moles in a substance given it's number of entities we use the formula

[tex]n = \frac{N}{L} \\[/tex]

where n is the number of moles

N is the number of entities

L is the Avogadro's constant which is

6.02 × 10²³ entities

From the question we have

[tex]n = \frac{4.07 \times {10}^{24} }{6.02 \times {10}^{23} } \\ = 6.760797...[/tex]

We have the final answer as

6.76 moles

Hope this helps you

What is the difference between moles and mass?

Answers

Mass is the state of motion when an external force is applied.

Moles in other hand is an unit for measuring the amount of substance.

For all of these it’s Explanation with support:
1. The color of a solution identifies if it is an acid, base, or neutral solution
2. Which solution is basic
3. How will adding water effect the pH

Answers

Answer:

1. A

Explanation:

1.A True we can identify solutions based on the color of the solutions. If you look at our  universal PH color chart. Red, Orange, and yellow are acids.

2. D, If you look at the pH levels. Both B and C have a pH level equal to or greater than 7. Note that any pH level 7 or higher is a basic solution.

3.A

Looking at the pH level we can see that this is an acidic solution. So, by adding more water. The acidity will lessen.

Which could cause renewable resources to change from renewable to non- renewable?

A. Pollution
B. Overuse
C. Disease
D. All of these

Answers

D. All the above

If you overuse a renewable resource, such as overfishing. Over time the fish will become non- renewable. If a renewable land is polluted eventually it will become non- renewable. Also if a species gets a disease it can make them become a non- renewable resource.
Other Questions
turns on her laptop and gets the error message "OS NOT FOUND." She checks the hard disk for damage or loose cable, but that is not the case. What could be a possible cause? Learning Task 2 without graphing tell whether the graphs of the system of equations are parallel, perpendicular,intersecting or coinciding 1.y = x + 7 and y = - x + 22.Y = 5x and y = 5x - 13. 2x + y = 1 and 2y + 4x = 24. Y = 2x + 3 and y = -x - 4 Aqueous solutions of lithium hydroxide (LiOH) and acetic acid (HC2H3O2) will react to yield lithium acetate and water. In the balanced equation for this reaction, what is the lowest possible whole number coefficient for water? ANSWER FAST PLSS !!!!!!!!! The glowing dot represents the transmission of a nerve impulse along the nerves that make up the neural pathway. A nerve impulse is an electrical signal that travels from one nerve cell to another.Which part of the brain processes this signal? use the distributive property to find the answer to 21 x 4 Q1. Solve the linear equation a) y - 3 = -5 Martin is comparing two different video game stores. *At Best Buy, the equation c=59.99g*At PC Richard & Son, the cost of 2 games is $117.96, and the cost of 5 games is $294.90How much money, per game would Martin save by going to the less expensive gas station?If you dont know plz dont answer it :)) What kind of health insurance involves a co-pay for doctor visits? O A. Managed care B. Fee-for-service C. Disability O D. Life how does whitmans statement reveal the values of individualism and democracy cherished by the emerging American culture Which statements about the Prussian revolution are true? Check all that apply.It was successful.O Results lasted less than a year.It was defeated.O Liberals were behind it.Nationalists were behind it. A student observes that a plant has droopy leaves and stems and infers that the rate of photosynthesis has slowed in the plant. Which statement provides evidence to support the students inference? Raise the product of 36 and 9 to the power of the sum of 2 and 4.Which of the following expressions matches the sentence above?A.(36 = 9(2+4)B.(36 x9)(2+4)O c.(36 x 9)(2x4)D.(36 = 9)2 + 4 What is a reasonable approach to investing in penny stocks? O Invest only if you are directly contacted by a broker. O Avoid completely because they are low-cost. O Treat with caution because they have uncertain rates of return. O Invest with confidence because they are so low-cost. If you were to leave the United States and go to live in Germany you would be called a(n):emigrantcitizenmigranttourist john swims 5/12 of a mile in 3/8 of an hour. What distance, in miles, does john swims in an hour?A.) 1 5/9B.)15/96C.)5/20D.)1 5/12 The regular price of a pair of sneakers is $80. They are on sale now for $50. What is the percent decrease in the price of sneakers? Jackie won tickets playing the bowling game at the local arcade. The first time, she won 60 tickets. The second time, she won a bonus, which was 4 times the number of tickets of the second prize. Altogether she won 200 tickets. How many tickets was the second prize? A culture trait is best defined as Which expression is equivalent to t+3+ 5 - 4t?