why is it dangerous to wear contact lenses in the lab

Answers

Answer 1

Answer:

It is strongly recommended that students do NOT wear contacts lenses in the laboratory. Chemical vapors may penetrate the contact lens material and cause the lens to adhere to one's eye, which could be detrimental to the eye. Goggles are not vapor tight and do not completely eliminate this absorption.


Related Questions

Three shining iron nails Kept unday the following conditions.

a) kept open in attest tube containing А wet cotton.

B )kept in a closed container quick lime

c) About half protein of the nail is kept immrest in sodium chloride solution




questions:-

1) al which of these nails get rusted ? o

2)identify the nail which does not undergo rusting Give reason

3)Suggest a method to prevent corrosion of iron​

Answers

Answer:

1. the nail which is kept immersed in Sodium Chloride solution

2.

Explanation:

What does it mean by solution in salt solution, sugar solution, etc.

Answers

Salt solution means water and salt mixed until dissolved.
Sugar solution means water and sugar mixed until dissolved.

PLEASE PEOPLE I NEED HELP PLEASE IF YOU SEE THIS HELP ME ! :,(



NO LINKS !!!! PLEASE :)

Answers

Answer: 5.5 7.5 102

Explanation: using the equation above you can get these %s

when a tennis ball is dropped from a high distance is it elastic or inelastic collision? explain?

Answers

Answer:

An elastic collision.

Explanation:

When a ball is dropped to the ground, one of four things may happen: It may rebound with exactly the same speed as the speed at which it hit the ground. This is an elastic collision.

pleaseee PLEASEEE PLEASEEE I NEED HELPPP!!

can someone do these for me I will give brainliest

Answers

1. 116mol
2. 40atm
3. 627C

noble gases are used in many situations where a safe and constant environment must be maintained. for example, helium is used to provide a protective atmosphere for making fiber optics and semiconductors. argon is used to fill incandescent and flourescent light bulbs to prevent oxygen from corroding the hot filament. why are noble gases used in these situations?

Answers

Answer:

Because they do not naturally react with other elements

Explanation:

Since noble gases do have a fulfilled valence shell, they do not react with other elements because they're already stable by the themselves.

30g of glucose and 20 g common salt is dissolved in 500 mL of water to make solution. Calculate the concentration of a (a) glucose and (b) common salt in terms of mass by mass percentage of the solution. (Density of water = 1 g/mL)​

Answers

Answer:

The answer of a is 5.45% and b is 3.64%

Explanation:

Density of water = 1 g/mL

∴ Mass of water (solvent) = 500 g

Mass of solute (glucose) = 30 g

Mass of solute (common salt) = 20g

Mass of solution = (30 + 20 + 500) g = 550 g

a.)

Mass percentage of solution for glucose

= Mass of solute (gucose)/Mass of solution × 100

= 30/550 x 100

= 5.45 %

b.)

Mass percentage of solution for common salt

= Mass of solute (common salt)/Mass of solution × 100

= 20/550 × 100

= 3.64 %

Thus, The answer of a is 5.45% and b is 3.64%

-TheUnknownScientist 72

Answer:

5.45%

and

3.64%

hope it's helpful

During the Cellular Respiration reaction glucose reacts with oxygen gas
to form water and Carbon Dioxide. How much carbon Dioxide would be formed from 58 grams of glucose?

Answers

try putting 66 grams CO2 for answer

How much energy is needed to convert 15.0 g of ice at -5.0 oC into water at 50.0 oC?

Answers

m=15g=0.015kg∆T=50-(-5)=55°C=328Kc=4184J/kg°K

Using thermodynamics

[tex]\\ \sf\longmapsto Q=mc∆T[/tex]

[tex]\\ \sf\longmapsto Q=0.015(328)(4184)[/tex]

[tex]\\ \sf\longmapsto Q=20585.28J[/tex]

How many molecules does 1 mole of Oz gas have?

Answers

awnser : 6.02×1023 molcules

Answer: One mole of oxygen gas, which has the formula O2, has a mass of 32 g and contains 6.02 X 1023 molecules of oxygen but 12.04 X 1023 (2 X 6.02 X 1023) atoms, because each molecule of oxygen contains two oxygen atoms

which acid is part of the white coating on sour patch kids?

Answers

Tartaric acid is the white, powdery substance that coats tart candies such as Sour Patch Kids. COmbustion analysis of a 12.01g sample of tartaric aid, which contains carbon, hydrogen and oxygen, produces 14.08g CO2 and 4.32g

H2O.

i would know because i have see what there made of

Which model of the atom is thought to be true?

A. Protons, electrons, and neutrons are evenly distributed throughout the volume of the atom.
B. The nucleus is made of protons, electrons, and neutrons.
C. Electrons are distributed around the nucleus and occupy almost all the volume of the atom.
D. The nucleus is made of electrons and protons.

Answers

Answer:

Hi the answer should be B or 2

Explanation:

Hope this helps!

Kelli and Jarvis are members of the stage crew for the Variety Show. Between acts, they must quickly move a Baby Grand Piano onto stage. After the curtain closes, they exert a sudden forward force of 524 N to budge the piano from rest and get it up to speed. The 158-kg piano experiences 418 N of friction. a. What is the piano's acceleration during this phase of its motion? b. If Kelli and Jarvis maintain this forward force for 1.44 seconds, then what speed will the piano have?

Answers

If Kelli and Jarvis maintain a forward force of 524 N for 1.44 seconds on a 158-kg piano, the acceleration will be 0.671 m/s² and the final velocity will be 0.966 m/s.

Kelli and Jarvis exert a force of 524 N on a 158- kg (m) piano.

The friction force, which opposes this force, is 418 N.

The net force (F) is the difference between both forces.

F = 524 N - 418 N = 106 N

We can calculate the acceleration (a) of the piano using Newton's second law of motion.

What is Newton's second law of motion?

Newton's second law of motion states that the acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force and inversely proportional to the mass of the object.

a = F/m = 106 N/158kg = 0.671 m/s²

The piano start from rest (u = 0 m/s) and moves with an acceleration of 0.671 m/s² for 1.44 s.

We can calculate its final velocity (v) using the following kinematic equation.

v = u + a × t

v = 0 m/s + 0.671 m/s² × 1.44 s = 0.966 m/s

If Kelli and Jarvis maintain a forward force of 524 N for 1.44 seconds on a 158-kg piano, the acceleration will be 0.671 m/s² and the final velocity will be 0.966 m/s.

Learn more about Newton's second law of motion here: https://brainly.com/question/10673278

How many molecules are in 0.750 moles of magnesium sulfide?

Answers

Answer:

4.51 x 10 to the 23 power

Explanation:

Determine the amplitude

or period as requested.


Period of y = 4sin 1/3x


a. 4

b. Pi/4

c. 4pi/3

d. 6pi

Answers

Answer:I found out that it is c

Explanation:Find an answer to your question Determine the amplitude or period as requested. Period of y = 4sin 1/3x a. 4 b. Pi/4 c. 4pi/3 d. 6pi.

Some tomato ketchup accidentally got onto a piece of white fabric. Your mother suggested that lemon juice, baking soda, or vinegar would be good for removing the tomato stain. Plan and design an experiment that can be used to investigate which of the three substances is most effective in removing the tomato stain.

1. Write a hypothesis for your investigation
2. Identify the dependent, independent, and controlled variables.
3. Outline a proposed method for the experiment you would conduct.
4. What data would be collected? Suggest a suitable way(s) for recording your data.
5. Identify ONE (1) possible source of error and ONE (1) precaution.

Please if you see this help me answer these questions.

Answers

Answer:

3... uhm I'm not sure it could 2

In the equation 2H2 + O2 → 2H20, what are the reactants?

Answers

Answer:

2H2 and O2

Explanation:

The energy required to cause a gaseous atom or ion to release a electron is what?

Answers

Answer:

The ionization energy

Explanation:

The ionization energy is required to cause a gaseous atom or ion to release a electron.

chemistry, giving brainliest !

Answers

the actual yield is i believe 20.03g
i may be wrong and if i am, i am extremely sorry and also sleep deprived

Answer:

20.03g

Explanation:

This is the formula for percentage yield:

Percentage yield = Actual Yield / Theoretical yield

Rearrange it to get the Actual yield, which would be:

Actual yield = Percentage yield (in decimal form) x Theoretical yield

We know that 75% of CO2 is produced as the percentage yield in a reaction and the theoretical yield for the mass we're supposed to find is 26.7 grams.

Percentage yield in decimal form: 0.75

Theoretical yield: 26.7g

Plug it in the equation

Actual yield = 0.75 x 26.7g

Actual yield = 20.03g

Oxygen-Carbon Dioxide Exchange
Place the statements in the correct
order.


1. heart pumps oxygen-
rich blood to the body
2. carbon dioxide moves
from bronchioles to bronchi
3. air moves through the
bronchi into the bronchioles
4. blood picks up carbon
dioxide from the body
5. INHALE
6. alveoli receive oxygen
to pass to blood
7. heart pumps carbon
dioxide rich blood to the
lungs
8. nose traps germs in air
9. oxygen passes into the
blood
10. air moves down the
trachea
11. alveoli receives carbon
dioxide from the blood
12. oxygen-rich blood flows to
the heart
13. carbon dioxide flows up
the trachea
14. EXHALE
15. carbon dioxide flows out
the nose and mouth

Answers

Answer:

Answer is below with the steps in order

Explanation:

4) Blood picks up carbon dioxide from the body

7) Heart pumps carbon dioxide rich blood to the lungs

8) Inhale

9) Nose traps germs in air

10) Air moves down the trachea

3) Air moves through bronchi into the bronchioles

6) Alveoli receive oxygen pass to blood

9) Oxygen passes into the blood

11) Alveoli receives carbon dioxide from the blood

12) Oxygen-rcih blood flows to the heart

3) Carbon Dioxide moves from bonchioles to bronchi

13)Carbon dioxide flows up

1) Heart pumps oxygen-rich blood to the body

The last four of five steps could be switched up a little bit since it all happens synchronously, but this is the most accurate interpretation.

The statements in the correct order are:

4) Blood picks up carbon dioxide from the body7) Heart pumps carbon dioxide-rich blood to the lungs8) Inhale9) Nose traps germs in the air10) Air moves down the trachea3) Air moves through bronchi into the bronchioles6) Alveoli receive oxygen pass to blood9) Oxygen passes into the blood11) Alveoli receives carbon dioxide from the blood12) Oxygen-rcih blood flows to the heart3) Carbon Dioxide moves from bonchioles to bronchi13)Carbon dioxide flows up1) Heart pumps oxygen-rich blood to the body.

Oxygen-Carbon Dioxide Exchange

The lungs and respiratory system allow us to breathe. They bring oxygen into our bodies (called inspiration, or inhalation) and send carbon dioxide out (called expiration, or exhalation). This exchange of oxygen and carbon dioxide is called respiration.

Learn more about Oxygen-Carbon Dioxide Exchange here: brainly.com/question/18521401

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Look at the diagram of metallic bonding. The light blue area represents a sea of... what?

Answers

Answer:

try elcetrons

Explanation:

if not then i'm sorry

The light blue area represents electrons.

What is an electron?

An electron is a negatively charged subatomic particle. It can be either free (not attached to any atom) or bound to the nucleus of an atom. Electrons in atoms exist in spherical shells of various radii, representing energy levels. The larger the spherical shell, the higher the energy contained in the electron.

What is the role of electrons?

Electrons play an essential role in numerous physical phenomena, such as electricity, magnetism, chemistry and thermal conductivity, and they also participate in gravitational, electromagnetic and weak interactions.

Learn more about electrons here: brainly.com/question/25674345

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How many moles are there in 10 dm3 of sulfur dioxide gas

Answers

Taking into account the room temperature and pressure, there are 0.4167 moles in 10 dm³ of sulfur dioxide gas.

RTP refers to Room Temperature and Pressure. Pressure is 1 atm and Temperature is 298K. In this case, one mole of any gas has a volume of 24 dm³ or 24,000 cm³. This volume is called the molar volume of a gas.

In other words, the molar volume (the amount of space occupied by one mole) of any gas is 24dm³ (1 mol of gas molecules occupies 24.0 dm³).

Therefore, the amount of volume occupied by any gas can be calculated by multiplying the number of moles of gas by 24dm³:

Volume = Moles of gas× 24 dm³

So, the number of moles can be calculated as:

Moles of gas= Volume÷ 24 dm³

In this case, you know that volume if sulfur dioxide gas is 10 dm³. So, replacing:

Moles of gas= 10 dm³ ÷ 24 dm³

Solving:

Moles of gas= 0.4167

Finally, there are 0.4167 moles in 10 dm³ of sulfur dioxide gas.

Learn more about Room Temperature and Pressure:

https://brainly.com/question/23119191?referrer=searchResults

Which atom has the largest atomic radius? *
1.Cl
2.F
3.I

Answers

Answer: 2

Explanation:I think

What is the atomic number of an atom?

Question 3 options:

the number of protons

the number protons and neutrons

the number of neutrons

the number of electrons and neutrons

Answers

Answer: The number of protons

Explanation:

The molar mass of water (H2O) is 18. 0 g/mol. A sample of water has a mass of 18. 0 g. How many moles of water are contained in this sample? 1. 00 18. 0 36. 0 324.

Answers

1 mole of water is contained in a sample of water that has a mass of 18.0 g.

HOW TO CALCULATE NUMBER OF MOLES:

The number of moles of a substance can be calculated by dividing the mass of that substance by its molar mass.

no. of moles = mass ÷ molar mass

According to this question, a sample of water has a mass of 18.0g. The number of moles is calculated as follows:

no. of moles of H2O = 18.0g ÷ 18g/mol

no. of moles of H2O = 1mol

Therefore, 1 mole of water is contained in a sample of water that has a mass of 18.0 g.

Learn more about mole calculations at: https://brainly.com/question/8101390?referrer=searchResults

which luquid is known as universal solvent?why?​

Answers

Answer:

Water.

Explanation:

it can dissolve more substances than any other liquid.

Water is called the "universal solvent" because it is capable of dissolving more substances than any other liquid. This is important to every living thing on earth.

I hop this helps! :)

In chemistry class, you are given a density column with 3 liquids (shown in the
image). A small sample of beryllium (a metal) with a mass of 2.8 grams and a volume
of 1.5 mL is added to the column. Where would the metal sample be located in the
column?

Answers

Answer:

A)

Explanation:

the wind pushes a paper cup along the sand at a beach. the cup has a mass of 0.025 kg and accelerates at a rate of 5 m/s2. how much force is the wind exerting on the cup

Answers

To find the force,

 ⇒ must know the force's formula ⇒ F = MA

M: mass of the objectA: acceleration of the object

Let's consider the information given:

cup has a mass of 0.025kg --> 'M'accelerates at a rate of 5 m/s^2 --> 'A'

Let's solve:

  [tex]F=MA=0.025kg*5m/s^2=0.125N[/tex]

Thus the force is 0.125N

Answer: 0.125N

Hope that helps!

Sodium has more valence electrons than magnesium.

True
False
Correct answers only please, no links. (15 points)

Answers

Answer:

False

Explanation:

hi! sodium has one valence electron while magnesium has 2. this is because of their position on the periodic table. sodium is the first in the row, meaning it has one valence electron. magnesium is next to sodium on the periodic table, meaning it is second in the row and has two valence electrons. hope this helps!

Which statement describes how a substance melts?(1 point) Molecules in the substance gain kinetic energy and then become less tightly bound to each other. Molecules in the substance gain kinetic energy and then become less tightly bound to each other. Molecules in the substance lose kinetic energy and then become more tightly bound to each other. Molecules in the substance lose kinetic energy and then become more tightly bound to each other. Molecules in the substance lose kinetic energy and then become less tightly bound to each other. Molecules in the substance lose kinetic energy and then become less tightly bound to each other. Molecules in the substance gain kinetic energy and then become more tightly bound to each other. Molecules in the substance gain kinetic energy and then become more tightly bound to each other.

Answers

Answer:

Molecules in the substance gain kinetic energy and then become less tightly bound to each other.

Explanation:

According to the forces of attraction , for a substance to melt molecules  in the substance gain kinetic energy and then become less tightly bound to each other.

What are forces of attraction?

Forces of attraction  is a force by which atoms in a molecule  combine. it is basically an attractive force in nature.  It can act between an ion  and an atom as well.It varies for different  states  of matter that is solids, liquids and gases.

The forces of attraction are maximum in solids as  the molecules present in solid are tightly held while it is minimum in gases  as the molecules are far apart . The forces of attraction in liquids is intermediate of solids and gases.

The physical properties such as melting point, boiling point, density  are all dependent on forces of attraction which exists in the substances.

Learn more about forces of attraction,here:

https://brainly.com/question/10957144

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