Which of the following presents a safety hazard while working in the science laboratory?
A knowing how to use equipment
B wearing safety goggles
C following directions
D working alone

Answers

Answer 1

Answer:

D working alone

Explanation:

Working alone is the only option that could potentially be a safety hazard; if you have no one watching your back, errors could occur, like dropping glass or burning your hand, and no one is around to help you.

Choices A, B, and C are not correct because those are all good safety standards.


Related Questions

Help me!

what is the biggest disadvantage of using nuclear power to produce electricity?

a. nuclear fission releases more air pollution than burning coal

b. nuclear fission produces less energy than burning coal or oil.

c. nuclear waste must be safely stored for many years

d. nuclear waste must be incinerated

Answers

The biggest disadvantage of using nuclear power to produce electricity is the nuclear waste must be safely stored for many years.

What is nuclear power?

Nuclear power is the use of nuclear reactions to produce electricity. Nuclear power can be obtained from:

Nuclear fission Nuclear decay and Nuclear fusion reactions

Nuclear reactions produces high amount of energy and many waste materials which are non degradable and will stay in the environment for the long time.

Hence, nuclear waste must be safely stored for many years.

To know more about nuclear power, visit the below link:

https://brainly.com/question/11963586

#SPJ2

Blast furnaces extra pure iron from the Iron(IIl)oxide in iron ore in a two step sequence. In the first step, carbon and oxygen react to form carbon monoxide:
2C(s)+O2(g) arrow 2CO(g)
In the second step, iron(lll) oxide and carbon monoxide react to form Iron and carbon dioxide:
Fe203(s) + 3CO(g) arrow 2Fe(s)+ 3CO2(g)
Suppose the yield of the first step is 71.% and the yield of the second step is 72.%. Calculate the mass of oxygen required to make 7.0 kg of iron.
Be sure your answer has a unit symbol, if needed, and is rounded to 2 significant digits.

Answers

Answer:

5.9 kg  

Explanation:

We must work backwards from the second step to work out the mass of oxygen.

1. Second step

Mᵣ:                                     55.84

            Fe₂O₃ + 3CO  ⟶  2Fe  +  3CO₂

m/kg:                                    7.0

(a) Moles of Fe

[tex]\text{Moles of FeO} = \text{7000 g Fe} \times \dfrac{\text{1 mol Fe}}{\text{55.84 g Fe}} = \text{125 mol Fe}[/tex]

(b) Moles of CO

[tex]\text{Moles of CO} = \text{125 mol Fe} \times \dfrac{\text{3 mol CO}}{\text{2 mol Fe}} = \text{188 mol CO}[/tex]

However, this is the theoretical yield.

The actual yield is 72. %.

We need more CO and Fe₂O₃ to get the theoretical yield of Fe.

(c) Percent yield

[tex]\begin{array}{rcl}\text{Percent yield} &=& \dfrac{\text{ actual yield}}{\text{ theoretical yield}} \times 100 \, \%\\\\ 72. \, \% & = & \dfrac{\text{188 mol}}{\text{actual yield}} \times 100 \,\%\\\\0.72 &= &\dfrac{\text{188 mol}}{\text{actual yield}}\\\\\text{Actual yield} & = & \dfrac{\text{188 mol}}{0.72}\\& = & \textbf{261 mol}\\\\\end{array}[/tex]

We must use 261 mol of CO to get 7.0 kg of Fe.

2. First step

Mᵣ:                32.00

            2C   +  O₂   ⟶  2CO

n/mol:                             261

(a) Moles of O₂

[tex]\text{Moles of O}_{2} = \text{261 mol CO} \times \dfrac{\text{1 mol O}_{2}}{\text{2 mol CO}} = \text{131 mol O}_{2}[/tex]

(b) Mass of O₂

[tex]\text{Mass of O}_{2}= \text{131 mol O }_{2} \times \dfrac{\text{32.00 g O}_{2}}{\text{1 mol O}_{2}} = \text{4180 g O}_{2}[/tex]

However, this is the theoretical yield.

The actual yield is 71. %.

We need more C and O₂ to get the theoretical yield of CO.

(c) Percent yield

[tex]\begin{array}{rcl}71. \, \% & = & \dfrac{\text{188 mol}}{\text{actual yield}} \times 100 \,\%\\\\0.71 &= &\dfrac{\text{4180 g}}{\text{actual yield}}\\\\\text{Actual yield} & = & \dfrac{\text{4180 g}}{0.71}\\\\& = & \text{5900 g}\\& = & \textbf{5.9 kg}\\\end{array}[/tex]

We need 5.9 kg of O₂ to produce 7.0 kg of Fe.

I AM GIVING BRAINLIEST PLEASEE HELPPPP I NEED HELPPPPPP PLEAEEEEEE
63.2 g of BaCl 2 are dissolved in enough water to make a 634 mL solution. What is the molarity?

Answers

Answer:

0.479 M or mol/L

Explanation:

So Molarity is moles/litres of solution...often written as M=mol/L

So here we are given grams of BaCl2 which we have to convert to moles. To convert to moles of BaCl2 we have to divide 63.2 g BaCl2 by molar mass of BaCl2 which is 208.23 g/mol so you get 63.2/208.23 = 0.3035 moles of BaCl2

Second step is converting the 634mL to litres by simply dividing by 1000 because we know 1 litre has 1000ml so 634/1000 = 0.634L

Now we just plug these guys in our molarity formula M=mol/L

M= 0.3035/0.634 = 0.479 M or mol/L

Answer:

Interestingly enough, I'm not getting

0.0341% w/v

either. Here's why.

Start by calculating the percent composition of chlorine,

Cl

, in calcium chloride, This will help you calculate the mass of chloride anions,

Cl

, present in your sample.

To do that, use the molar mass of calcium chloride, the molar mass of elemental chlorine, and the fact that

1

mole of calcium chloride contains

2

moles of chlorine atoms.

2

×

35.453

g mol

1

110.98

g mol

1

100

%

=

63.89% Cl

This means that for every

100 g

of calcium chloride, you get

63.89 g

of chlorine.

As you know, the mass of an ion is approximately equal to the mass of the neutral atom, so you can say that for every

100 g

of calcium chloride, you get

63.89 g

of chloride anions,

Cl

.

This implies that your sample contains

0.543

g CaCl

2

63.89 g Cl

100

g CaCl

2

=

0.3469 g Cl

Now, in order to find the mass by volume percent concentration of chloride anions in the resulting solution, you must determine the mass of chloride anions present in

100 mL

of this solution.

Since you know that

500 mL

of solution contain

0.3469 g

of chloride anions, you can say that

100 mL

of solution will contain

100

mL solution

0.3469 g Cl

500

mL solution

=

0.06938 g Cl

Therefore, you can say that the mass by volume percent concentration of chloride anions will be

% m/v = 0.069% Cl

−−−−−−−−−−−−−−−−−−−

I'll leave the answer rounded to two sig figs, but keep in mind that you have one significant figure for the volume of the solution.

.

Explanation:

how many Atoms of chlorine Cl are there in 3.45 mol Cl?

Answers

Answer:

2.078x10^24

Explanation:

No. of atoms of chlorine = 3.45 x 6.022x 10 ^23 x 1

= 2.078x10^24

( to find no. of atoms of, heres the formula i was taught No. of atoms = no. of moles x Avogadros constant x no. of atoms in the formula of compound)

What does X represent for this transmutation?

 96242Cm + X→ 98245Cf +  01n

gamma
 +10e
 24He
 −10e

Answers

Answer:

 24He

Explanation:

When a nuclide is bombarded with alpha particles, we notice an increase in its mass and charge since an alpha particle has a mass of four and a charge of +2. recall that nuclear equations must be balanced. That is, the masses and charges on the left hand six and the right hand side of the nuclear reaction equation must be exactly the same.

Looking at the nuclear reaction at hand, the total mass on the left hand side has to be 246 while the total charge on the left hand side of the equation will be 98. Coming over to the right hand side, the total masses are also found to be the same as a neutron with no charge and a mass of 1 is produced. Hence the nuclear reaction equation is balanced when an alpha particle (helium nucleus) is substituted for X in the equation.

Answer:

24HE

I took the test!

Which statement best describes liquid water and water vapor at equilibrium?
A. Liquid water stops entering the gas phase.
O B. The concentration of liquid water equals the concentration of
water vapor.
C. The concentrations of liquid water and water vapor are stable.
D. The concentration of liquid water is zero.

Answers

C. The concentrations of liquid water and water vapor are stable. it describes the fact that liquid water and water vapor are at equilibrium.

EquilibriumAn equilibrium is achieved when no more water vapor can enter into the gas phase from the liquid water during evaporation process. This happens when a saturation is attained between liquid water and the vapor phase.

Hence, option (c) is correct. The concentration of liquid water and water vapor will become stable.

Learn more about water vapor:

https://brainly.com/question/17259832

Where do diamonds come from?

Answers

Answer: Diamonds were first discovered and mined in India over 2,400 years ago.

Explanation: Over time, diamonds were found in many other areas around the world, including many in Africa. In today's trade, Africa, Russia, Australia, and Canada produce the most diamonds.

~Wonderopolis

Answer:

Diamonds are formed when under the heat and pressure of the earth's gravity.  Diamonds have to be underground to be formed so they should be underground. Digging to Y11 is deep enough to find diamonds .

How are electrons similar and different to the planet Earth?

Answers

Answer:

The planets themselves are composed of several trillions or quadrillions or more atoms. As far as hard science is concerned, it would be really hard to picture them as electrons. Conclusion: It can be said with a great accuracy that our planets are NOT huge electrons.

Rutherford's experiments showed that the mass of atoms was mostly concentrated in a very small region, with charge equal to the atomic number- the nucleus. He absolutely did not show, nor is it true, that electrons orbit the nucleus as if they were planets. That was a guess people made in trying to figure out how to picture the atom.

(Hope this helps) Sky

What improvements have been made in modern farming? Select all that apply.

1. machines can do more work over less time
2. better seeds sprout and grow much more quickly
3. trains can transport food over long distances faster
4. trains can transport the machines to rural farms once built
5. insecticides used to keep insects off the crops

Answers

Answer:

all of them except number 2

Explanation:

Answer:

1,3,4,5  the other perosn is correct

Explanation: That what my quiz said

Need help with these three pls!!!!!

Answers

True because

False

True
1) true , 2) false , 3) true

Fiona is examining a material. She notices that the material has a dull appearance and feels very brittle.

Fiona is most likely examining a _______

(I'll give brainliest)

Answers

"Typical nonmetals have a dull, coloured or colourless appearance; are brittle when solid; are poor conductors of heat and electricity; and have acidic oxides." - Wikipedia

Fiona is most likely examining a nonmetal.

What slows down heat energy from escaping the Earth?

Answers

There are some gases in the atmosphere which trap the heat escaping from the Earth and stop it from travelling back into space. These gases are called greenhouse gases. The glass in a greenhouse has a similar effect on the Sun's rays and so it is called the Greenhouse Effect.

Answer:

Greenhouse gases such as carbon dioxide and water vapor make an atmosphere around the earth and make less heat escape

Explanation:

How many joules are produced when 45 gram of copper is placed into water that releases them temperature from 12c to 71c (c)=0.75j/g*c

Answers

Answer:

Heat energy (Q) = 1.9925 KJ = 2 KJ (Approx)

Explanation:

Given:

Mass of copper (M) = 45 gram

Change in temperature (ΔT) = 71°C - 12°C = 59°C

Specific heat (c) =0.75 j /g*c

Find:

Heat energy (Q) = ?

Computation:

Heat energy (Q) = Mass(M) × Change in temperature (ΔT) × Specific heat (c)

Heat energy (Q) = 45 gram × 59°C × 0.75 j /g*c

Heat energy (Q) = 1991.25 J

Heat energy (Q) = 1.9925 KJ = 2 KJ (Approx)

Brandon is trying to remember how the physical and chemical properties of metals, nonmetals, and metalloids compare. He wrote some notes down, then looked in his textbook to see which notes were correct.

Which of Brandon's notes, listed below, are correct?
I. Metals are the best at conducting heat, and nonmetals are the worst.
II. Metals are the worst at conducting electricity, and nonmetals are the best.
III. The shape of nonmetals is easy to change, but the shape of metals or metalloids is difficult to change.
IV. Nonmetals are dull in appearance while metals are usually shiny.
V. Metals tend to have a high density, and nonmetals tend to have a low density.

Answers

Answer:

The correct ones are:

|

|||

|V

V

Explanation:

Answer:

1 for and 5

Ex

Study island

How can the motion of atoms in the solid state of most substances be described?









Answers

Answer:

The molecules in a solid are stuck in a specific structure or arrangement of atoms. The atoms still vibrate and the electrons fly around in their orbitals, but the entire atom will not change its position.

what happens to the density of a box full of leaves if you crush up all the leaves and place them in another box

A the density increases

B the density stays the same

C the density decreases

D the density first decreases, then increases

Answers

Answer:

B the density stays the same

PLZ HELP OR WILL FAIL!!

Label A drop downs are: condensation, melting, sublimation

Label B drop downs are: condensation, melting, sublimation

Label C drop downs are: condensation, melting, sublimation

Answers

Hey there!

Label A: Sublimation
Label B: Condensation
Label C: Melting

Remember sublimation is the transition of a substance directly from the solid to the gas state, without passing through the liquid state. Condensation is the conversion of a vapor or gas to a liquid. Melting is becoming liquefied by heat.

Hope this helps!

Which of these Electromagnetic waves has the most kinetic energy and can be
dangerous?
O radio waves
O gamma rays
O ultraviolet waves
O visible light

Answers

Answer:

Gamma Rays.

Explanation:

Gamma-ray photons have the highest energy in the EMR spectrum and their waves have the shortest wavelength.

Why did the United States government set aside land for the first national parks?


A.

They wanted to settle the west as quickly as possible.


B.

They worried people would destroy the animals and land.


C.

They worried Native Americans wouldn’t have anywhere to go.


D.

They wanted to make sure all citizens would get a piece of land.

Answers

B) They worries people would destroy the animals and land.

Answer:

b

Explanation:

hope it helps

Which sentence best describes part of the process for generating electricity in a nuclear power plant?
A.Atoms Join together to produce water molecules.
B.An atom releases electrons, producing an electric current.
C.Protons and neutrons Join together to create atoms.
D.Heat is released when atomic nuclel split.​

Answers

Answer:it is D

Explanation: it is only one that makes sense

aight imma let you guys i

Answers

Answer:

b

Explanation:

it is right

Ksskskskdkejdidkk bysco sskkskskskskskskskskskkskskskskskskskkssk

what is an example of a strong base?

HCl
NaCl
NaOH
HF

Answers

Answer:

The answer is NaOH

Explanation:

Strong bases are characterized by the fact that they dissociate completely in an aqueous solution. In this case, sodium hydroxide, NaOH, is classified as a strong base because it dissociates completely in an aqueous solution to form sodium cations, Na+, and hydroxide anions, OH−. Also, it is strong because it totally breaks in its ion. And the base which breaks totally in its atom called the strong base and which doesn't it that is a weak base.

Answer:

NaOH

Explanation:

Got it right in the test. Please mark as brainliest

The process by which complex compounds are broken down by enzymes and by which many organic alcohols are formed is called

Answers

Answer:

fermentation

Explanation:

Why is soap mixed with water?
O A. The soap turns the water molecules into a nonpolar solvent.
B. It covalently bonds to the water so it can be washed away.
O C. Its polar end mixes with the water so it can be washed away.
D. The soap becomes chemically active when mixed with water.

Answers

Answer:

Explanation:

Soap breaks up the oil into smaller drops, which can mix with the water. It works because soap is made up of molecules with two very different ends. One end of soap molecules love water - they are hydrophilic. The other end of soap molecues hate water - they are hydrophobic.

Answer:

C. Its polar end mixes with the water so it can be washed away.

Explanation:

Just took test

A typical cell phone uses wavelength of 0.36meters. How much energy does this wave have?

Answers

Answer:

55×10^-26 J

Explanation:

We can calculate the energy of the wave from

E= hc/λ

Where

h= Planks constant = 6.6×10^-34 Is

c= speed of light = 3×10^8 ms-1

λ= wavelength of the wave = 0.36 metres

Recall that cell phone use radio waves which belong to the electromagnetic spectrum hence it must possess the speed of light.

E= 6.6×10^-34 × 3×10^8/ 0.36

E= 55×10^-26 J

Hence the energy possessed by 0.36 meters wavelength radio waves is 55×10^-26 J

What is the primary role of the United States Bureau of Counterterrorism?
о
to plan counterterrorist attacks
to create active counterterrorism groups
to encourage domestic counterterrorism activities
to advance counterterrorism efforts in other countries

Answers

o advance counterterrorism efforts in other countries

Answer:

D

Explanation:

E2020

Which equilibrium describes a reversible reaction a short time after starting the reaction with reactants only?

Answers

Answer:

Should be A

Explanation:

Compare and contrast the dynamics of energy transfer between the Eocene Period and the Cryogenian Period. In which period would you say that Earth's system is experiencing a net gain in energy and in which period would you say that Earth's system is experiencing a net loss in energy

Answers

Answer:

The Eocene Period is experiencing net gain in energy while Cryogenian Period is experiencing a net loss in energy.

Explanation:

In Eocene Period, the population of mammals such as horses , whales and bats etc were high due to the presence of high amount of food and good atmospheric condition such as high temperature while the population of animals were low in Cryogenian Period due to the presence of very low temperature which experiencing loss of energy. Most of area of the earth consist of icy desert.

If is known how deep the water table in an area is, it is known how deep to dig to reach


Pores

The unsaturated zone

Solid rock

Groundwater

Answers

Answer:
Groundwater

Explanation:
Groundwater is really soft to go through as sand.

Answer:

grond water

Explanation:

0.450 moles of K2SO4 are dissolved in 195.0 mL of water. Calculate the molarity of the solution.

Answers

Answer:

2.31M

Explanation:

The following data were obtained from the question:

Mole of K2SO4 = 0.450 mole

Volume of water = 195.0 mL = 195/1000 = 0.195L

Molarity =...?

Molarity is defined as the mole of solute per unit litre of the solution. This can be expressed as:

Molarity = mole /Volume

With the above formula we can calculate the molarity of the K2SO4 solution as follow:

Molarity = mole /Volume

Molarity = 0.450/0.195

Molarity = 2.31M

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The table shows the cost in dollars, y, for renting a pair of snow skis or renting a snowboard for x days. Which function shows the combined cost in dollars, y, for renting two pairs of snow skis and two snowboards for x days? y = 45x + 60 y = 90x + 120 y = 25x + 25 y = 20x + 35 Prior to WWI, what were the countries of Europe competing for Read the selection from the section "The ItalianRenaissance in context."The rich people of Florence showed offtheir money by paying for artists andthinkers. They were called patrons ofthese artists, and made the city into thecultural center of Europe,Which phrase from the selection BEST helps thereader understand the meaning of "patrons"? 1)Which is NOT a service provided by local government? -conduct elections -trash pick-up -community speed limits -establish Post Offices 2)The job of the state's Executive Branch is to carry out and enforce state laws. t or f3)Local governments get their power from the U.S. Constitution. t or f4)Which of the following does NOT require a state license? -Dentist -Private Investigator -Fitness Instructor -Teacher 5)Setting school requirements such as graduation requirements is a local decision or a state decision? 6)Passing a law or ordinance that bans people from having livestock or barnyard animals is type of local or state law? The Constitution party advances a conservative approach to issues and would most likely support policies that __________.A.reflect our basic principlesB.disregard the Bill of RightsC.expand the role of the governmentD.expand our foreign policy intervention leadership is theprocess ofOthers to accomplish.a. mission If P (7, 5) and P' (2,8) then the rule for translation is PLS HELP THIS IS A LOT OF PIONTS SO BE FAST So i forgot what the genetic code is and how its read can somebody please be kind and help me.. Who was the economist who led a new school of classical economics? How do u say ironic in spanish The quarterback Tom Brady completes 60% of his passes. To simulate the outcome of a single pass we use the digits 0, 1, 2, 3, 4, and 5 to represent the outcome "the pass is completed" and the digits 6, 7, 8, and 9 to represent the outcome "the pass is not completed." To be confident that our simulation is accurate, one needs to : A. Repeat the simulation several more times B. Assign new digits to represent outcomes C. Take the average of the results of Line 134 and Line 101 "In the midst of evil you want to be a good man. You want decency.You want justice and courtesy and human concord, things you never knew you wanted."What is the irony of the above quote from the passage? PLZZZ HELP CHEM!!!!!!! Easy points!!!!! Which number line shows the solutions to n Choose the option that best matches the description given.information assurance is a type of: 1.computer virus 2.cuber security 3.engineering The equation of certain traveling waves is y(x.t) = 0.0450 sin(25.12x - 37.68t-0.523) where x and y are inmeters, and t in seconds. Determine the following:(a) Amplitude. (b) wave number (C) wavelength. (d) angular frequency. (e) frequency: (1) phase angle, (g) thewave propagation speed, (b) the expression for the medium's particles velocity as the waves pass by them, and (i)the velocity of a particle that is at x=3.50m from the origin at t=21.os Help me!what is the biggest disadvantage of using nuclear power to produce electricity?a. nuclear fission releases more air pollution than burning coalb. nuclear fission produces less energy than burning coal or oil.c. nuclear waste must be safely stored for many yearsd. nuclear waste must be incinerated The armistice with Germany was signed by What clues tell you that this is a compare and contrast text structure