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3 years ago

The electrons of an atom are (2 points)

Chemistry

2 answers:

Oksana_A [137]3 years ago

8 0

Are negatively charged particles that's what it is your welcome:)

pshichka [43]3 years ago

8 0

The electrons of an atom are the negatively charged particles.

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How are science and technology related

KatRina [158]

There is no answer, science is about empirical knowledge, technology is the sum of techniques, skills, methods, and processes. I do not believe that you will find a answer for that.

7 0

3 years ago

The stopper-puncturing needle should be completely pushed into the evacuated tube:__________. A. after the vein is entered. B. w

brilliants [131]

Answer:

The correct answer is:

after the vein is entered (A.)

Explanation:

The procedure in the question describes venopuncture.

Venopuncture is the method of aseptically collecting blood into the right sample containers. Using a stopper-punturing needle and a vacuum tube, the following procedure is followed:

assemble the needle and hub (needle holder)
apply the tourniquet and examine the arm for palpable vein, palpate the vein
release the tourniquet and swab the collection site with 70% alcohol
allow the swab to dry
reapply the tourniquet
insert the stopper-puncturing needle (attached to hub) into the appropriate vein
after the vein is entered, the stopper-puncturing needle should be completely pushed into the evacuated (vacuum) tubes
blood will flow into the tube until vacuum is completely filled
pull out the tube and invert gently several times if the tube contains anticoagulants
place a gauze on the site of puncture (do not press down the gauze)
remove the needle and press down the gauze immediately
dispose the needle into the sharps container or appropriately
label the tubes.

6 0

3 years ago

Watching the assignment without knowing how to solve the questions is the worst thing to experience hope someone can help with t

frez [133]

Answer:

- 622.5kJ

Explanation:

1) 2NH3 + 3N2O ----> 4N2 + 3H2O ΔH° 1= - 1010kJ

- 3 (N2O + 3H2 ---> N2H4 + H2O ΔH° 2 = - 317 kJ)

2) 2NH3 + 3N2O ----> 4N2 + 3H2O ΔH° 1= - 1010kJ

- 3N2O - 9 H2 ----> - 3N2H4 - 3H2O - 3ΔH° 2 = 3*317 kJ

2NH3 + 3N2H4 --->4N2+9H2, ΔH° 1 - 3*ΔH° 2

2NH3 + 3N2H4 --->4N2+9H2, ΔH° 1 - 3*ΔH° 2

3) -(2NH3 +1/2O2 ---> N2H4 + H2O, ΔH°3 = -143 kJ)

-2NH3 - 1/2O2 ---> - N2H4 - H2O, - ΔH°3 = 143 kJ

2NH3 + 3N2H4 --->4N2+9H2, ΔH° 1 - 3*ΔH° 2

-2NH3 - 1/2O2 ---> - N2H4 - H2O, - ΔH°3 = 143 kJ

4N2H4 + H2O ---> 4N2 + 9H2 + 1/2O2, ΔH° 1 - 3*ΔH° 2 - ΔH°3

H2 + 1/2O2 ---> H2O, ΔH° 4 = - 286 kJ

9*(H2 + 1/2O2 ---> H2O, ΔH° 4 = - 286 kJ)

9H2+ 9/2 O2 ---> 9H2O, 9*ΔH° 4 = 9*(- 286) kJ

4N2H4 + H2O ---> 4N2 + 9H2 + 1/2O2, ΔH° 1 - 3*ΔH° 2 - ΔH°3

9H2+ 9/2 O2 ---> 9H2O, 9*ΔH° 4 = 9*(- 286) kJ

4N2H4 +4O2 --->4N2+8H2O, ΔH° 1 - 3*ΔH° 2 - ΔH°3 + 9*ΔH° 4

1/4*(4N2H4 +4O2 --->4N2+8H2O, ΔH° 1 - 3*ΔH° 2 - ΔH°3 + 9*ΔH° 4

N2H4 +O2 --->N2+2H2O, 1/4( ΔH° 1 - 3*ΔH° 2 - ΔH°3 + 9*ΔH° 4)

N2H4 +O2 --->N2+2,

1/4( ΔH° 1 - 3*ΔH° 2 - ΔH°3 + 9*ΔH° 4)=

=1/4(-1010kJ - 3*(-317kJ) - (-143kJ) + 9*(-286kJ))= - 622.5 kJ

7 0

3 years ago

If 10.0 liters of oxygen at STP are heated to 785.15 °K, what will be the new volume of gas if the pressure is also increased to

Ugo [173]

Answer: The new volume of gas is 28.5 L

Explanation:

The combined gas equation is,

$\frac{P_1V_1}{T_1}=\frac{P_2V_2}{T_2}$

where,

$P_1$ = initial pressure of gas = 1.00 atm (at STP)

$P_2$ = final pressure of gas = 102.6 kPa = 1.01 atm (1 kPa= 0.0098 atm)

$V_1$ = initial volume of gas = 10.0 L

$V_2$ = final volume of gas = ?

$T_1$ = initial temperature of gas = $273.15K$ (STP)

$T_2$ = final temperature of gas = $785.15K$

Now put all the given values in the above equation, we get:

$\frac{1.00\times 10.0}{273.15}=\frac{1.01\times V_2}{785.15}$

$V_2=28.5L$

The new volume of gas is 28.5 L

8 0

3 years ago

A compound was decomposed and determined to be 51.27 % C, 7.75 % H and 40.98 % O by mass. What is the subscript for H in the emp

Vlad [161]

The subscript for H in the empirical formula for this compound is 3.

There are 3 steps involved in the construction of empirical formula.

Calculation of empirical formula is as under as ...

Step 1: Divide the % of each atoms which their atomic weights.

C = 51.27 / 12 = 4.27

H = 7.75 / 1 = 7.75

O = 40.98 / 16 =2.56

Step 2 : Divide all the answers with the smallest answer to get the subscripts for empirical formula.

C = 4.27/ 2.56 ≈ 2

H = 7.75/ 2.56 ≈ 3

O = 2.56 /2.56 = 1

Step 3: Construction of empirical formula by putting subscripts calculated in step 2.

Empirical formula form given data = $C_{2} H_{3} O_{1}$

Thus , subscript for H in the empirical formula for this compound is 3.

Learn more about empirical formula here..

brainly.com/question/13058832

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4 0

2 years ago