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Fittoniya [83]
3 years ago
8

1. Lani conducted an experiment in which she tested the reactivity of a substance. She placed two

Chemistry
1 answer:
Dima020 [189]3 years ago
4 0

Answer:

the independent variable is the beakers

Explanation:

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What is the answers and pls show work if possible!!
taurus [48]

D = m / V


It even gives you the density of gold in the problem. Major hint. Once you know the volume (using V = m / D) then you can calculate the height (thickness) from the equation...


V = L x W x H

Volume = Length x Width x Height


start by converting 200.0 mg into grams

1000 mg = 1 g

200. mg x (1 g / 10^3 mg) = 0.200 g


V = m / D

V = 0.200 g / (19.32 g/cm^3)

V = 0.01035 cm^3


Convert 2.4 ft and 1 ft to cm

2.4 ft x (12 in / 1 ft) x (2.54 cm / 1 in) = 73.15 cm

1 ft = 30.48 cm


Compute the height (thickness)

V = LxWxH

H = V / LW = 0.01035 cm^3 / 73.15 cm / 30.48 cm

H = 4.64 x 10^-6 cm


Convert to nanometers

4.64 x 10^-6 cm x (1 m / 100 cm) x (10^9 nm / 1 m) = 46.4 nm


Knowing the atomic radius of gold, I might have asked my students for the minimum number of gold atoms in this thickness of gold. This would assume that the gold atoms are all in a row. This would give the minimum number of gold atoms.


Atomic radius gold = 174 pm

Diameter = 348 pm


46.4 nm x (1 m / 10^9 nm) x (10^12 pm / 1 m) x (1 Au atom / 248 pm) = 133 atoms of gold


4 0
3 years ago
If
defon

Answer:

If

0.0357

mol

CaCl

2

is dissolved in water to make a

0.420

M

solution, what is the volume of the solution?

4 0
3 years ago
An important reaction that takes place in a blast furnace during the production of iron is the formation of iron metal and CO2 f
ladessa [460]

Answer: Mass of Fe_2O_3 required to form 930 kg of iron is 1328 kg

Explanation:

To calculate the number of moles, we use the equation:

\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}      .....(1)

For iron:

Given mass of iron = 930 kg = 930000 g  (1kg=1000g)

Molar mass of iron = 56 g/mol

Putting values in equation 1, we get:

\text{Moles of iron}=\frac{930000g}{56g/mol}=16607mol

The chemical equation for the  production of iron  follows:

Fe_2O_3+3CO\rightarrow 2Fe+3CO_2

By Stoichiometry of the reaction:

2 moles of iron are  produced by =  1 mole of Fe_2O_3

So, 16607 moles of iron will be produced by = \frac{1}{2}\times 16607=8303moles of Fe_2O_3

Now, calculating the mass of Fe_2O_3 from equation 1, we get:

Mass of Fe_2O_3 = moles\times {\text {molar mass}}=8303\times 160=1328480g=1328kg

Thus mass of Fe_2O_3 required to form 930 kg of iron is 1328 kg

6 0
3 years ago
How many valence electrons are in the element gallium? explain how you determined the number.
Natasha2012 [34]

Answer:

three valence electrons

Explanation:

Gallium has three electrons in the outer energy level and therefore has three valence electrons. The identification of valence electrons is vital because the chemical behavior of an element is determined primarily by the arrangement of the electrons in the valence shell.

4 0
3 years ago
Which types of clouds are bright white ad fluffy,sometimes forming shapes or pictures?
lawyer [7]
The answer is cumulus. 

Stratus clouds often low and sometimes confused for fog. Cirrus clouds are thin and wispy.
4 0
3 years ago
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