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3 years ago

Metalloids have properties of both metals and nonmetals a. True b. False

Chemistry

2 answers:

astra-53 [7]3 years ago

7 0

True. It’s in the name

barxatty [35]3 years ago

3 0

Answer:

true

Explanation:

did it on edge2020

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Which of the following statements about photophosphorylation is FALSE? Energy from oxidation reactions is used to generate ATP f

kolbaska11 [484]

Answer:

The FALSE statement is: It requires CO2.

Explanation:

Photophosphorylation is a process during which solar energy, in the form of a proton, impact on chlorophyll, exciting one electron. The excited electron pass along different carriers (Ferredoxin, cytochrome b6f and Plastocyanin) and eventually return to its origin. This electron passage promotes the formation of ATP from ADP (one molecule ATP is formed when three electrons pass throug the cycle).

3 0

3 years ago

a compound contains two elements, sulfur and oxygen. in a sample of the compound, the mass of sulfur is 6.41 grams. the mass of

Scrat [10]

Percent composition is mass of element over mass of compound times 100. 6.41 + 9.60 = 16.01 g of compound, so % composition of sulfur is 6.41/16.01 x100 or 40.0%. % oxygen is 9.60/16.01 x 100 or 60.0%.

4 0

3 years ago

Calculate the mass of chloroform that contains 1.00X10^12 molecules of chloroform

Brums [2.3K]

<span>Molar mass of chloroform (CHCl3)
C = 1 * 12 = 12 a.m.u
H = 1 * 1 = 1 a.m.u
Cl = 3 * 35.5 = 106.5 a.m.u
Molar Mass (CHCl3) = 12 + 1 + 106.5 = 119.5 g / mol

Knowing that: The value of Avogadro's constant corresponds to approximately </span> $6,02*10^{23}$ molecules, if chloroform contains $1,00 * 10^{12}$ molecules. <span>
We have:

</span> $1,00 * 10^{12} * 6,02 * 10^{23} = 6,02 * 10 ^ {35} molecules$ <span>

Now, how many grams are there in the chloroform molecule?

grams -------- molecules</span><span>
119,5 </span>→ $6,02 * 10^{23}$
x → $6,02 * 10^{35}$

$6,02 * 10 ^ {23} * x = 119,5 * 6,02 * 10 ^{35}$
$6,02 * 10 ^ {23}x = 719,39 * 10^{35}$
$x = \frac{719,39}{6,02}*10^{35-23}$
$\boxed{x = 119,5*10^{12}grams}$

7 0

3 years ago

7. A gas has a volume of 300 mL at 300 mm Hg. What will its volume be if the pressure is changed to 500 mm Hg?

USPshnik [31]

Answer:

The volume is

Explanation:

In order to solve for the volume we use the formula for Boyle's law which is

where

P1 is the initial pressure

V1 is the initial volume

P2 is the final pressure

V2 is the final volume

Since we are finding the final volume we are finding V2

Making V2 the subject we have

From the question

P1 = 300 mmHg

V1 = 300 mL

P2 = 500 mmHg

Substitute the values into the above formula and solve for the final volume obtained

That's

<h3> $V _{2} = \frac{300 \times 300}{500} \\ = \frac{90000}{500} \\ = \frac{900}{5}$ </h3>

We have the final answer as

Hope this helps you

7 0

3 years ago

Two separate masses of zinc were measured on a laboratory balance. The first zinc had a sample mass of 210.10g, and the second z

wlad13 [49]

Answer:

Density is 7.15 g /mL.

Mass is 445.2 g.

Explanation:

Density:

Density is equal to the mass of substance divided by its volume.

Units:

SI unit of density is Kg/m3.

Other units are given below,

g/cm3, g/mL , kg/L

Formula:

D=m/v

D= density

m=mass

V=volume

Symbol:

The symbol used for density is called rho. It is represented by ρ. However letter D can also be used to represent the density.

Given data:

Mass of first zinc sample = 210.10 g

Mass of second zinc sample = 235.10 g

Combined volume = 62.3 mL

Density of combined sample ?

Mass of combined sample = ?

Solution:

Mass of combined sample = 210.10 g + 235.10 g = 445.2 g

density = mass / volume

density = 445.2 g / 62.3 mL

density = 7.15 g /mL

3 0

3 years ago