The stopper-puncturing needle should be completely pushed into the evacuated tube:__________. A. after the vein is entered. B. while the equipment is being assembled. C. just before the vein is entered. D. prior to anchoring the vein.

Answer:

680

Explanation:

Move the decimal 2 to the right.

When a number is written using only the digits of the number, that is considered standard notation. 6.8 × 10²  is converted into standard notation by shifting two decimal to the right side, then it became 680.

A form of writing a certain number, an equation, or an expression in a way that adheres to set norms is known as a standard notation. For instance, 4,500,000,000 years is how 4.5 billion years is written.

When a number is written using only the digits of the number, that is considered standard notation. Since words are not used in conventional number notation, this is the way that numbers are typically written.

The stages to writing a number in its standard form are as follows: Write the first digit of the supplied number in step one. Step 2: After the first number, add the decimal point. Step 3: Next, count how many digits there are in the supplied number after the first one and express that number as a power of 10.

Thus, the standard notation is 680.

To learn more about standard notation, follow the link;

https://brainly.com/question/10253124

#SPJ2

Answer:

0.307 g

Explanation:

Step 1: Given data

Volume of solution: 100.0 mL

Molarity of the NaCl solution: 0.0525 M

Molar mass of NaCl: 58.44 g/mol

Step 2: Calculate the moles of NaCl required

The molarity is equal to the moles of solute (NaCl) divided by the liters of solution.

M = moles of NaCl / liters of solution

moles of NaCl = M × liters of solution

moles of NaCl = 0.0525 mol/L × 0.1000 L = 5.25 × 10⁻³ mol

Step 3: Calculate the mass corresponding to 5.25 × 10⁻³ moles of NaCl

5.25 × 10⁻³ mol × 58.44 g/mol = 0.307 g

Answer:

Pb(NO₂)₂(aq) + 2 LiCl(aq) ⇒ PbCl₂(s) + 2 LiNO₂(aq)

Explanation:

Let's consider the reaction between aqueous lead (II) nitrite and aqueous lithium chloride to form solid lead (II) chloride and aqueous lithium nitrite.

Pb(NO₂)₂(aq) + LiCl(aq) ⇒ PbCl₂(s) + LiNO₂(aq)

This is a double displacement reaction. We will start balancing Cl by multiplying LiCl by 2.

Pb(NO₂)₂(aq) + 2 LiCl(aq) ⇒ PbCl₂(s) + LiNO₂(aq)

Now, we have to balance Li by multiplying LiNO₂ by 2.

Pb(NO₂)₂(aq) + 2 LiCl(aq) ⇒ PbCl₂(s) + 2 LiNO₂(aq)

The equation is now balanced.

The balanced chemical reaction equation required is; Pb(NO2)2(aq) + 2 LiCl(aq) -----> PbCl2(s) + 2LiNO2(aq)

In order to write a balanced chemical reaction equation, we must write down the symbols of the compounds involved as follows;

lead (II) nitrite  - Pb(NO2)2

lithium chloride - LiCl

lead (II) chloride - PbCl2

lithium nitrite - LiNO2

Recall that the principle of writing a balanced chemical reaction equation is that the number of atoms of each element on both sides of the reaction equation must be the same. The required balanced chemical reaction equation is;

Pb(NO2)2(aq) + 2 LiCl(aq) -----> PbCl2(s) + 2LiNO2(aq)

Learn more: https://brainly.com/question/2320755

Answer:

P=110 m

Explanation:

Length of the field is 38 m

Breadth of the field is 17 m

We need to find the perimeter of this field. It is in the form of a rectangle. The perimeter of a rectangle is given by :

P=2(l+b)

P=2(38+17)

P=110 m

So, the perimeter of this field is 110 m.

Answer:

diamond

sugar

rubber

salt (NaCl)

wood

ice

flour

Answer:

diamond

sugar

salt

ice

Explanation:

Answer:

It will take the police car 3.5 hours to travel a distance of 175 miles traveling at a rate of 50 miles/hour.

Explanation:

Answer: m=F/a

Explanation:

Answer:

d

Explanation:

Answer:

b) At equilibrium, equal amounts of products and reactants are present.

Explanation:

At equilibrium , the ratio of product of concentration of products  and product of concentration of  reactants is constant .

                                             A + B ⇄ C + D

                                 [C] [ D]  / [ A ] [ B ] = Constant

So, the statement ( b )  is false .

All other statements are true .

Answer:

pH = -log₁₀ [H⁺]

Explanation:

pH is a value in chemistry used in to measure solution trying to determine each quality, purity, risks for health of some products, etc.

As you write in the question, [H⁺] = 10^(-pH)

Using logarithm law (log (m^(p) = p log(m):

log₁₀ [H⁺] = -pH

And

Answer:

7 (a neutral solution)

Answer: 10-7= 0.0000001 moles per liter

5.6 (unpolluted rainwater)

Answer: 10-5.6 = 0.0000025 moles per liter

3.7 (first acid rain sample in North America)

Answer: 10-3.7 = 0.00020 moles per liter

The concentration of H+ in the Hubbard Brook sample is 0.00020/0.0000025, which is 80 times higher than the H+ concentration in unpolluted rainwater.

Explanation:

plato

Answer:

94 are naturally made on earth

Explanation:

Answer:

94 or 98, i think.

Explanation:

Answer:

H2O - Hydrogen bonding, dipole dipole, and dispersion

CH4 - Dispersion only

CO - Dipole dipole and dispersion only

CH3Cl - Dipole dipole and dispersion only

Explanation:

Hydrogen bonding can only exist when hydrogen is bonded to a small highly electronegative atom such as oxygen hence hydrogen bonds, dipole interactions and dispersion by are present in water.

CH4 is a nonpolar molecule hence only dispersion forces are present.

CH3Cl and CO both possess dipoles in the molecule hence both dipole interactions and dispersion forces exist in the molecule.

If the reaction is a chemical change, new substances with different properties and identities are formed. This may be indicated by the production of an odor, a change in color or energy, or the formation of a solid.

Answer:

1. A. 10°C

2. A. Boiling point

3. A. Less than liquids.

Explanation:

Answer:

The structures are shown in the attachments.

Explanation:

Please see the attachments below for the structures.

Explanation:

There is only one environment denoted as 'a'.

Using the (n+1) rule to determine the multiplicity, m

where is the number of neighboring Hydrogen, then

Since, n = 0, then

m = 0 + 1 = 1 (which means singlet)

Hence, one singlet

There are two environments denoted as 'a' and 'b'

For 'a' ; n = 6

Hence, m = n + 1

m = 6 + 1  = 7 (this means septet)

For 'b'; n = 1

then, m = n + 1

m = 1 + 1  = 2 (this means doublet)

Hence, one septet, one doublet

There are two environments denoted as 'a' and 'b'

For 'a' ; n = 2

then, m = n + 1

m = 2 + 1  = 3 (this means triplet)

For 'b' ; n = 2

then, m = n + 1

m = 2 + 1  = 3 (this means triplet)

Hence, two triplets

There are three environments denoted as 'a', 'b', and 'c'

For 'a' ; n = 0

Hence, m = n + 1

m = 0 + 1  = 1 (this means singlet)

For 'b' ; n = 3

then, m = n + 1

m = 3 + 1  = 4 (this means quartet)

For 'c' ; n = 2

then, m = n + 1

m = 2 + 1  = 3 (this means triplet)

Hence, one singlet, one triplet, and one quartet

Answer:

The volume of first and second compound are 9.15 ml and 10.85 ml.

Explanation:

Given that,

Density of graphite = 2.25 g/cm³

Volume of mixture = 20.0 mL

Density of first compound = 1.492 g/ml

Density of second compound = 2.890 g/ml

Let the volume of first mixture = x

The volume of second mixture = (20-x)....(I)

We need to calculate the volume of first compound

Using formula of  density of mixture

[tex]\rho=\dfrac{V_{1}\rho_{1}+V_{2}\rho_{2}}{V_{1}+V_{2}}[/tex]

Where, [tex]V_{1}[/tex] = volume of first compound

[tex]V_{2}[/tex] = volume of second compound

[tex]\rho_{1}[/tex] =density of first compound

[tex]\rho_{1}[/tex] = density of first compound

Put the volume into the formula

[tex]2.25=\dfrac{x\times1.492+(20-x)\times2.890}{x+20-x}[/tex]

[tex]45=1.492x+57.8-2.890x[/tex]

[tex]45-57.8=1.492x-2.890x[/tex]

[tex]12.8=1.398x[/tex]

[tex]x=\dfrac{12.8}{1.398}[/tex]

[tex]x=9.15\ ml[/tex]

We need to calculate the volume of second compound

Using equation (I)

[tex]V_{2}=20-x[/tex]

Put the value of x

[tex]V_{2}=20-9.15[/tex]

[tex]V_{2}=10.85\ ml[/tex]

Hence, The volume of first and second compound are 9.15 ml and 10.85 ml.

The ans should be C. ( if i'm not wrong )

This is because the solubility of oxygen increases when temperature in the water is cooler. Cold water can hold more dissolved oxygen than warm water, thus having a higher concentration of oxygen.

Answer:

C. is greater in cool liquid water than in warm liquid water.

Explanation:

Answer:

I would say it's A just because it's make no sense for the other answers.

Aluminum atom is most likely to form a metallic bond.

METALLIC BONDS:

Learn more: https://brainly.com/question/20511339?referrer=searchResults

Answer:

1. 0.209quart

2. 743.6pounds

3. 22500kg/m^3

4. 2.07pounds

5. 4.50cm

Explanation:

Note that, these questions are related to density which can be calculated using the formula:

Density (p) = Mass (m) / Volume (v)

However, the units are different for each questions, hence, must be made the same

1. 1 ounce = 28.35 grams

95 ounces will be 95 × 28.35 = 2693.2g

Volume = mass/density

Volume of Mercury= 2693.2/13.6

Volume= 198ml

1 ml = 0.00106quart

198ml = 198 × 0.00106 = 0.209quart

2. 1 gallon = 3785.4ml

55 gallons = 55× 3785.4 = 208197ml

Mass = density × volume

Mass = 1.62 × 208197

Mass = 337,279.14g

1 pounds = 453.592 g

337279.14 g = 337279.14/453.592

Mass = 743.6pounds

3. 1g/cm^3 = 1000kg/m^3

Hence, a density of 22.5g/cm^3 will be 22.5 × 1000 = 22500kg/m^3

4. Volume of a cube of side 5cm each will be 5×5×5 = 125cm^3

Density = 7.50g/cm^3

Mass = Density×volume

Mass in grams = 7.50 × 125

Mass = 937.5grams

1 pound = 453.592 g

Therefore, 937.5g will be 937.5/453.592 = 2.07pounds.

5. Volume = Mass / density

Volume = 500/10.5

Volume = 47.62cm^3

Since a ball is spherical in shape, volume of a sphere (V) = 4/3πr^3

To find radius, we say;

47.62 = 1.33 × 3.142 × r^3

47.62 = 4.179 × r^3

r^3 = 47.62/4.179

r^3 = 11.395

r = 3√11.395

r = 2.25cm

To get diameter (d), we multiply the radius (r) by 2,

d = 2 × 2.25

d= 4.50cm

Answer:

Assume that the sack was initially close to the sea level. Its weight will increase even though its mass stays the same.

Explanation:

The weight of an object typically refers to the size of the planet's gravitational attraction (a force) on this object. That's not the same as the mass of the object. The weight of an object at a position depends on the size of the gravitational field there; on the other hand, the mass of the object is supposed to be same regardless of the location- as long as the object stays intact.

Let [tex]g[/tex] denote the strength of the gravitational field at a certain point. If the mass of an object is [tex]m[/tex], its weight at that point will be [tex]m \cdot g[/tex].

Indeed, [tex]g \approx 9.81\; \rm N \cdot kg^{-1}[/tex] on many places of the earth. However, this value is accurate only near the sea level. The equation for universal gravitation is a more general way for finding the strength of the gravitational field at an arbitrary height. Let [tex]G[/tex] denote the constant of universal gravitation, and let [tex]M[/tex] denote the mass of the earth. At a distance [tex]r[/tex] from the center of the earth (where

[tex]\displaystyle g \approx \frac{G \cdot M}{r^2}[/tex].

The elevation of many places in Bhutan are significantly higher than that of many places in India. Therefore, a sack of potato in Bhutan will likely be further away from the center of the earth (larger [tex]r[/tex]) compared to a sack of potato in India.

Note, that in the approximation, the value of [tex]g[/tex] is (approximately, because the earth isn't perfectly spherical) inversely proportional to the distance from the center of the planet. The gravitational field strength

On the other hand, the weight of an object of fixed mass is proportional to the gravitational field strength. Therefore, the same bag of potatoes will have a smaller weight at most places in Bhutan compared to most places in India.

Explanation:

A dishonest scientst has a lot of integrity.

Confirmation bias is the most common type of bias in science.

Answer: ethical scientists make unbiased conclusions, science is based on opinion and subjective evidence, and bias can be ruled out if similar results are obtained from repeated experiments.

Explanation: If you’re a dishonest scientist you don’t have integrity and confirmation bias isn’t the most common type of bias in science

Answer:

0.1

tenth

hundredth (0.01)

1.05 (can be anywhere from 1.00 to 1.10)

11.42 (can be anywhere from 11.40 to 11.50)

yes, it falls within reasonable doubt

Answer:

a. CH_3OH and Na^+

Explanation:

Ion-dipole interaction is the forces of attraction existing between a polar compound and an ion. This particular type of ion-dipole attraction occurs between an electrostatic attraction of an ion and a dipole molecule.

From the given example, CH3OH is a polar compound, and Na^+ is an ion. Therefore, that is the only pair that exhibit the characteristics of an ion-dipole interaction.

Given :

a. [tex]BH_x[/tex] b. [tex]CH_x[/tex] c. [tex]NH_x[/tex] d. [tex]CH_2Cl_x[/tex] .

To Find :

Find the most likely vale of x for each one .

Solution :

a . [tex]BH_x[/tex]

Because boron have valency of 3 .

So , x = 3 .

b . [tex]CH_x[/tex]

Valency of carbon is 4 .

x = 4 .

c . [tex]NH_x[/tex]

Valency of nitrogen is 3 .

Therefore , x = 3 .

d . [tex]CH_2Cl_x[/tex]

Now ,we know valency of carbon is 4 and hydrogen is 1 .

Also , two hydrogen are already there .

So , only 2 electrons left to share .

Since , chlorine have valency of 1 .

Therefore , only 2 electrons of chlorine can connect .

x = 2 .

Hence , this is the required solution .

Answer:

o-bromotoluene, m-bromotoluene  and p-bromotoluene.

Explanation:

Hello,

In this case, on the attached picture you will find the reaction which yields o-bromotoluene as the first product, m-bromotoluene as the second product and p-bromotoluene as the last one since the substitution could be done at the second (ortho), third (meta) or fourth (para) carbons on the toluene.

Regards.

Answer: 45.983 g CBr₄

Explanation:

To convert from moles to grams, you know that we will need molar mass and Avogadro's number.

Avogadro's number: 6.022×10²³ molecules/mol

Molar mass: 331.627 grams/mol

Now that we have what we need, you can use these to solve for grams. [tex]8.35*10^2^2molecules CBr_{4} *\frac{1mol}{6.022*10^2^3molecules} *\frac{331.627 g}{1 mol} =45.983 g[/tex]

Our final answer is 45.983 g CBr₄.

Answer:

This replacements will make the compound less basic and more acidic

Explanation:

Replacing amino groups (-NH₂) which act as bases [because of there ability to accept hydrogen ion (H⁺)] with carboxyl group (-COOH) which acts as acid [because of it's ability to donate hydrogen ion (H⁺)] in a compound changes the property of the compound to be less basic and more acidic.

Answer:

[tex]d=1x10^{-9}dm[/tex]

Explanation:

Hello,

In this case, considering that 1 m equals 10 dm, the required diameter of the atom in decimetres is:

[tex]d=1x10^{-10}m*\frac{10dm}{1m} \\\\d=1x10^{-9}dm[/tex]

Best regards.

Answer:

(a) N₂O - Dinitrogen monoxide or Dinitrogen (I) oxide

(b) NO - Nitrogen monoxide or Nitrogen (II) oxide

(c) NO₂ - Nitrogen dioxide or Nitrogen (IV) oxide

(d) N₂O₅ - Dinitrogen pentoxide

(e) N₂O₄ - Dinitrogen tetraoxide.

Explanation:

To name each of the compounds,

(a) N2O; It is properly written as N₂O. N₂O is a colorless, sweet tasting gas also known as "laughing gas".

N₂O - Dinitrogen monoxide OR Dinitrogen (I) oxide.

(b) NO; NO is a colorless gas.

NO - Nitrogen monoxide OR Nitrogen (II) oxide.

(c) NO2; It is properly written as NO₂

NO₂ is a reddish-brown gas.

NO₂ - Nitrogen dioxide or Nitrogen (IV) oxide.

(d) N2O5; It is properly written as N₂O₅

N₂O₅ is a white solid.

N₂O₅ - Dinitrogen pentoxide.

(e) N2O4; It is properly written as N₂O₄;

N₂O₄ is a red-brown liquid with an unpleasant smell.

N₂O₄ - Dinitrogen tetraoxide.