10 things you should never do while making a measurement in chemistry

Answers

Answer 1

Answer:

Measure at the top of the meniscus

Hold the container (it is unsteady)

Explanation:

I'm really, really, sorry. I took chemistry in 6th grade and I'm in 8th, and I don't remember the entire list. This is all I could think of.


Related Questions

How many molecules are in Na2CrO4

Answers

Answer:

It is 161.97324 g/mol

1 molecule

In general, atoms that have a high electronegativity have a ____ first ionization energy and a ____ atomic radius.
NEED ASAP
Select one:
a. low, small
b. high, large
c. low, large
d. high, small

Answers

Answer:

The correct option is D

Explanation:

Firstly, let's define the periodicity of these terms and then draw  conclusion from there.

Ionization energy is the amount of energy required to remove an electron from a gaseous atom in it's ground state. This property increases across a group in the periodic table.

Electronegativity is the measure of the property/tendency of an atom to attract an electron. This property also increases across a period. Thus, elements that have high electronegativity also have a high ionization energy.

Atomic radius is however the distance between the central nucleus to the outermost electron. This property decreases across the period. Thus, as electronegativity and ionization energy increases, atomic radius decreases.

From the above, it can be deduced that the correct option is d

Answer:high,small

Explanation:

I have the same test and I got it right

The pressure inside a hydrogen-filled container was 2.10 atm at 21 ∘C. What would the pressure be if the container was heated to 91 ∘C?

Answers

Answer:

[tex]P_2=2.60atm[/tex]

Explanation:

Hello!

In this case, since the temperature and pressure are related via a directly proportional relationship, via the Gay-Lussac's law we can write:

[tex]\frac{P_1}{T_1} =\frac{P_2}{T_2}[/tex]

Thus, since the initial temperature in kelvins is 294.15 K and the final temperature in kelvins is 364.15 K, we can compute the final pressure as shown below:

[tex]P_2=\frac{P_1T_2}{T_1} =\frac{2.10atm*364.15K}{294.15K}\\\\P_2=2.60atm[/tex]

Best regards!

Answer:

2.63 atm

Explanation:

the answer is 2.63 atm

8. ______________ and _____________ are located in the nucleus.

Answers

Answer:

protons and neutrons are located in the nucleus.

How would I find the answer?

Answers

Answer:

Kr

Explanation:

The noble gas that is isoelectronic with Br⁻ is krypton.

This is because krypton is the closest noble gas to Br on the periodic table.

Electronic configuration of Bromine is;

            2, 8, 18, 7

  Br⁻ becomes;  2, 8, 18, 8

  Krypton is;       2, 8, 18, 8

The noble gases can be found in group/period ____

Answers

Answer:

group 18

Explanation:

The noble gases (Group 18) are located in the far right of the periodic table and were previously referred to as the "inert gases" due to the fact that their filled valence shells (octets) make them extremely nonreactive

Answer:group 18

Explanation

Which of the following statement best defines matter?

Answers

show us the statements

Which shows three human body parts in order from the simplest level of organization to the most complex?

red blood cell → nervous system → bone tissue
nervous system → bone tissue → red blood cell
red blood cell → heart tissue → circulatory system
bone tissue → red blood cell → nervous system

Answers

Answer:

red blood cell → heart tissue → circulatory system

Explanation:

The levels of organization from the simplest level of organization to the most complex is cell, tissue, organ, organ, organ system, and organism. Red blood cells are cells, heart tissue is tissue in the heart and the circulatory system is an organ system that ensures blood, oxygen, and nutrients are flowing through the body.

Red blood cell → heart tissue → circulatory system shows the  three human body parts in order from the simplest level of organization to the most complex.

What is heart?

Heart is a muscular organ which is present in most of the animals , it is responsible for pumping blood via the blood vessels to the entire body.The blood which is pumped carries oxygen and nutrients along with it.Along with it on it's way back to heart it carries carbon dioxide to the lungs.

Heart has an approximate size of a closed fist and is present between the lungs in the middle compartment of the chest. It is divided in to for chambers , the upper chambers called atria and lower ones called ventricles.

The wall of the heart is made up of three layers : epicardium,myocardium and endocardium. It pumps blood with a rhythm which is determined by a group of cells which are called the pacemaker cells present in the sinoatrial node.

Learn more about heart,here:

https://brainly.com/question/16566688

#SPJ6

How many molecules are present in 4.21 moles of HBr?​

Answers

Answer:

The answer is

2.53 × 10²⁴ molecules

Explanation:

The number of molecules present can be found by using the formula

N = n × L

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

N = 4.21 × 6.02 × 10²³

We have the final answer as

2.53 × 10²⁴ molecules

Hope this helps you

1. When waves go from one place to another, they transport
A. amplitude
C. frequency
B. wavelength
D. energy

Answers

I believe it’s b, but correct me if I’m wrong!

In some places, timber companies remove all the trees from entire hillsides when they are
harvesting logs, and farmers till the soil in the fall and leave the ground bare of plants until it is
time to plant in spring. What is the most likely effect of doing either of these things?
A
A. Plants will sprout better.
B. Erosion will happen faster.
C. Soil will stay cooler.
D. Decomposition will speed up.

Answers

Answer:

c

Explanation:

soil will stay cooler

Help in history class please Thnks

Answers

Answer:

C) Foreign relations and war powers

6 List What are two advantages and two
limitations of physical models?
Plz help

Answers

Answer:

Physical models can represent objects or systems that are too small, too big, or too far away to study. They are way easier, cheaper, and safer to work with or use when compared to the real objects that they represent.

Explanation:

What creates a weather front?

Answers

A weather front is a transition zone between two different air masses at the Earth's surface. Each air mass has unique temperature and humidity characteristics. Often there is turbulence at a front, which is the borderline where two different air masses come together. The turbulence can cause clouds and storms.

Balance the reaction below using the correct coefficient.

__Ag2S --> __Ag + __S8

Answers

Answer:

8Ag2S--->16Ag+S8

Explanation:

thats your answer hope it helps

Which one is bigger proton or atom

Answers

Proton is bigger than an atom
Answer:

Aroma are bigger than protons.
Protons are smaller than atoms.

Explanation:

Inside a nucleus are neutrons and protons, which occupy a space about 100,000 times smaller than the whole atom.

A hydrogen atom is 100,000 times bigger than the proton that sits in the middle of it!

A chemist prepares a solution of magnesium fluoride MgF2 by measuring out 0.0113μmol of magnesium fluoride into a 450.mL volumetric flask and filling the flask to the mark with water. Calculate the concentration in /mmolL of the chemist's magnesium fluoride solution. Round your answer to 3 significant digits.

Answers

Answer:

2.51x10⁻⁵ mmol MgF2/L

Explanation:

To find the concentration in mmol / L we need to convert μmol to mmol (1000μmol / 1mmol) and mL to Liters (1000mL / 1L) as follows:

μmol MgF2:

0.0113μmol MgF2 * (1mmol / 1000μmol) = 1.13x10⁻⁵ mmol MgF2

Liters solution:

450mL * (1L / 1000mL) = 0.450L

Concentration in mmol/L:

1.13x10⁻⁵ mmol MgF2 / 0.450L =

2.51x10⁻⁵ mmol MgF2/L

Will the boiling point of water be higher or lower in the maintains, where the altitude is high, and the pressure is low ?

Answers

Higher low preccure

What happens during nuclear reaction that does not happen during a chemical reaction?

Answers

A chemical reaction does not create or destroy matter, it simply moves electrons from one atom to another, but does not change the nucleus of the atoms. ... The total mass of the matter can change during a nuclear reaction, the mass loss can convert into energy, which is called the nuclear power.

What is the name of the groups that contain Iron(Fe) and Gold(Au)?

Answers

Answer:

Transition Metals

Explanation:

Answer:

Group 8 & 11

Explanation:

Transition Metals

If you had to choose,
Happiness or Power? (Any type of Power)

Answers

Answer:

I will choose Happiness, Happiness, Happiness, Happiness.....

☺️❤️

Explanation:

Why Happiness Matters

It's the feeling of truly enjoying your life, and the desire to make the very best of it. Happiness is the "secret sauce" that can help us be and do our best. Here's what researchers found when they studied happy people: Happy people are more successful.

Scientific evidence suggests that being happy may have major benefits for your health. For starters, being happy promotes a healthy lifestyle. It may also help combat stress, boost your immune system, protect your heart and reduce pain. What's more, it may even increase your life expectancy.

While performing a neutralization reaction, Jonna added 22.63 mL of 0.142 M H2SO4 to 46.21 mL of 0.304 M KOH. How many moles of OH- are unreacted in the solution after the neutralization is complete?

Answers

Answer:

7.623 x 10⁻³ mol OH⁻

Explanation:

The reaction that takes place is:

H₂SO₄ + 2KOH → K₂SO₄ + 2H₂O

Now we calculate how many moles of each reagent were added:

H₂SO₄ ⇒ 22.63 mL * 0.142 M = 3.213 mmol H₂SO₄KOH ⇒ 46.21 mL * 0.304 M = 14.05 mmol KOH

We calculate how many OH⁻ moles reacted with H₂SO₄:

3.213 mmol H₂SO₄ * [tex]\frac{2mmolOH^-}{1mmolH_2SO_4}[/tex] = 6.427 mmol OH⁻

Finally we substract the OH⁻ moles that reacted from the added ammount of OH⁻ moles:

14.05 mmol KOH - 6.427 mmol OH⁻ = 7.623 mmol OH⁻7.623 mmol /  1000 = 7.623 x 10⁻³ mol OH⁻

The number of moles of OH⁻ that are unreacted in the solution after the neutralization reaction is complete is 0.00770 moles OR 7.70×10⁻³ moles

First, we will write a balanced chemical equation for the neutralization reaction

The balanced chemical equation for the neutralization reaction is

H₂SO₄ + 2KOH → K₂SO₄ + 2H₂O

This means

1 mole of H₂SO₄ reacts with 2 moles of KOH to give 1 mole of K₂SO₄ and 2 moles of H₂O

To determine the number of moles of OH⁻ that are unreacted after the neutralization is complete,

We will determine the number of moles of KOH remaining in the solution after the neutralization reaction is complete

First, we will determine the number of moles of each reactant present

For H₂SO₄

Volume = 22.36 mL = 0.02236 L

Concentration = 0.142 M

From the formula,

Number of moles = Concentration × Volume

∴ Number of moles of H₂SO₄ = 0.142 × 0.02236

Number of moles of H₂SO₄ = 0.00317512 moles

For KOH

Volume = 46.21 mL = 0.04621 L

Concentration = 0.304 M

∴ Number of moles of KOH = 0.304 × 0.04621

Number of moles of KOH = 0.01404784 moles

(NOTE: This is equal to the number of moles of OH⁻ at the beginning of the reaction)

From the equation of reaction, we have that

1 mole of H₂SO₄ will neutralize 2 moles KOH

Therefore,

0.00317512 moles of H₂SO₄ will neutralize 2×0.00317512 moles KOH

2×0.00317512 = 0.00635024 moles

This means only 0.00635024 moles of KOH reacted

(NOTE: This is equal to the number of moles of OH⁻ that reacted)

Now, for the number of moles of unreacted OH⁻

Number of moles of unreacted OH⁻ = Total number of moles OH⁻ at the beginning of the reaction - Number of moles of OH⁻ that reacted

∴ Number of moles of unreacted OH⁻ = 0.01404784 moles - 0.00635024 moles

Number of moles of unreacted OH⁻ = 0.0076976 moles

Number of moles of unreacted OH⁻ ≅ 0.00770 moles OR 7.70×10⁻³ moles

Hence, the number of moles of OH⁻ that are unreacted in the solution after the neutralization is complete is 0.00770 moles OR 7.70×10⁻³ moles

Learn more here: https://brainly.com/question/13190988

During winter, you can sometimes ice skate outdoors on a frozen lake. Why can’t you ice skate on a lake when it is not frozen?

Answers

Answer:

Generally the ice should be more than 4 inches thick to skate on it safely. However, the ice thickness is not always even and there can be thin spots, especially near springs or near river inlets or outlets. Most lakes and ponds don't completely freeze because the ice (and eventually snow) on the surface acts to insulate the water below. Our winters aren't long or cold enough to completely freeze most local water bodies. This process of lakes turning over is critically important to the life in the lake.

Explanation:

When the lake it’s frozen, it’s usually a liquid. So you’d probably sink

Iron, an element with the chemical symbol Fe, is an important element. It is used to make steel and is part of the substance that transports oxygen throughout the human body.

Which statement about Fe is supported by the modern atomic theory but not John Dalton’s theory?
A. The element iron is composed of small particles called atoms.
B. The electrons of iron have probable locations in a region of space around the nucleus.
C. Iron atoms combine with other atoms in whole number ratios to form compounds.
D. Chemical reactions that involve iron do not create new atoms of iron.

Answers

Answer:

i think its B

Explanation:

Answer:

aaaaaaaaa

Explanation:

Are light and other forms of energy are made of atoms

Answers

Answer:

yes they are

Explanation:

yes. everything is made of atoms

A(n)___ is the smallest neutral unit of two or more atoms held together by a covalent bond? ​

Answers

Answer:

A(n)___ is the smallest neutral unit of two or more atoms held together by a covalent bond? ​

=>MOLECULE

name the intermolecular force between Ne in liquid​

Answers

Answer:

Intermolecular forces in liquid are

Intermolecular forces are electrostatic in nature and include van der Waals forces and hydrogen bonds. Molecules in liquids are held to other molecules by intermolecular interactions, which are weaker than the intramolecular interactions that hold the atoms together within molecules and polyatomic ions.

Answer:

it is found in the halogen ,the no le gases and in other non polar molecules such as co2 and methane. Landon dispersion force are part of the Vander waals force or weak intermolecular attraction

Is NH4CIO3 ionic or ionic using the stock system or molecular

Answers

Answer:

I believe it would be ionic using the stock system.

Explanation:

The only difference is the size of cations, Cs+ being larger than Na+ and hence Na+ will have more polarising power than Cs+ and hence NaCl will be more covalent than CsCl or in other words CsCl will be more ionic than NaCl.

Solution A is 100 times as acidic as solution B. What is the difference in pH values of solution A and solution B

Answers

Answer:

The difference is 2 pH units.

Explanation:

Let's give an arbitrary value to the H⁺ concentration of solution A, [H⁺]ₐ:

[H⁺]ₐ = 0.001 M

If that's the case then the pH of solution A would be:

pHₐ = -log(0.001) = 3

----

The H⁺ concentration of solution B ( [H⁺]ₓ ) is 100 higher than that, so:

[H⁺]ₓ = 0.001 * 100 = 0.1 M

And its pH:

pHₓ = -log(0.1) = 1

So the difference in pH values is:

pHₐ - pHₓ = 3 - 1 = 2

Look at the picture below. Name the isotope

Calcium-19
Calcium-39
Potassium-20
Potassium-39

Answers

It is potassium 39 definately
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Evan spent 20 hours doing homework last week. This week he spent 25 hours doing homework. He says that he spent 125% more time doing homework this week. Is he correct? Show your work to justify your decision. (5 points) After Jeannette gets a divorce what type of the does she choose to live a life devoted to her parents she decided to devote her life to non profit worker a life of luxury a simple life from the glass castle book 10 POINTS!!!IS IT TRUE THAT AN APPLE, POTATO, AND ONION ALL TASTE THE SAME IF YOUR NOSE IS PLUGGED??? AND IF IT IS TRUE WHAT DOES IT TASTE LIKE??? See the case 1 and 2 These are the question I will give brainliest A. If you remove a bulb from case 1 , will the other bulb still light? Explain why.B. If you remove a bulb from case 2, will the other bulb still light? Explain why C. In which circuit do you think he bulbs glow. Brighter? Explain whyPoints and brainliest 4) What are all the subsets of (3, 5, 7)? My finals are coming up, any tips in general? can someone help with these two problems? What are the local, state, and national governments that have control over the community in which you live?I'll mark you brainliest!!!!! But I must tell you, when I was young in Paris, strange things happened to me. And these things had never happened to me before. When I left St. Louis a long time ago, the conductor directed me to the last car. And you all know what that means.Identify one type of rhetorical devices used in paragraph and what sentence is it? A weighted coin has a 0.599 probability of landing on heads. What is the probability that it takes 5 flips for the first head to occur? why is a school considered an important agent of socialization? select 1 factor that most likely reflects your life as a senior high student GYM MEMBERSHIP The cost of a gym membership is $75 plus $30 per month. The equation that represents this equation is y=30 x+75, where x is the number of months and y is the cost. Find and interpret f(12). You have the option to deposit $6500 into an account that pays 3.25% interest, compounded quarterly OR to deposit your money into an account that pays the same interest rate but compounds continuously. Which option yields you more money after 5 years and how much more? OPTIONS:Compounded quarterly, $4809.13Compounded quarterly, $416.23Compounded continuously, $5.02Compounded continuously, $878.52 3-paragraph essay on your opinion about its validity and relevance in today's society. (LC)Match the sentence to its correct label. (5 points)Column A1.She played video games all day long without stopping.:She played video games all day long without stopping.2.Without ceasing, she gripped her controller in her hands and dominated her video games all day long.:Without ceasing, she gripped her controller in her hands and dominated her video games all day long.3.For what had the quality of time interminable, she toiled merrily at her digital amusement.:For what had the quality of time interminable, she toiled merrily at her digital amusement.Column Ba.Overuse of Thesaurusb.Mature Writingc.Immature Writing Please help, explain if you know??????? 5(2y-3)-4y=8-2y-15Justify each step with a property of algebra. Drag the property to the correct row. Which of these results in kinetic energy of an object? PLEASE HELP!!Write an equation to represent the following statement.51 divided by 3 is k.Solve for k.