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3 years ago

Who created the first compound microscope and telescope?

Chemistry

2 answers:

vesna_86 [32]3 years ago

8 0

Answer:

Janssen

Explanation:

-BARSIC- [3]3 years ago

6 0

Answer:

Hans Martens/Zacharias Janssen

Explanation:

Janssen was the son of a spectacle maker named Hans Janssen, in Middleburg, Holland, and while Zacharias is credited with inventing the compound microscope, most historians surmise that his father must have played a vital role, since Zacharias was still in his teens in the 1590s.

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The beakers in the picture above are labeled according to the ionic solutions they contain. What metal or metals could replace c

tangare [24]

Explanation:

When a metal replaces another metal in solution, we say such a reaction has undergone a single displacement reaction.

In such a reaction, metal higher up in the activity series replaces another one due to their position.

To known the metal or metals that will replace the given copper, we need to reference the activity series of metals.

Every metal higher than copper in the series will displace copper from the solution.

So, there metals are: potassium, sodium, lithium, barium, strontium etc.

8 0

3 years ago

A functional group introduces heteroatoms into a carbon chain to increase

ivanzaharov [21]

Answer:

reactivaty

Explanation:

here you go for the answer

5 0

3 years ago

Olympic cyclists fill their tires with helium to make them lighter. Assume that the volume of the tire is 860 mL , that it is fi

nata0808 [166]

Answer:

a) the mass of air = 8.24 grams

b) the mass of helium = 1.14 grams

c) the mass difference = 7.10 grams

Explanation:

Step 1: Data given

Volume of the tire = 860 mL

Total pressure = 120 psi

Temperature = 26°C

molar mass of air = 28.8 g/mol

Step 2: Convert psi to atm

(

120 psi) (1 atm / 14.7 psi) = 8.163

Step 4: Calculate moles

PV = nRT

⇒ with P = the pressure = 8.163 atm

⇒ with V = the volume = 860 mL = 0.860 L

⇒ with n = the number of moles = TO BE DETERMINED

⇒ with R = the universal gas constant = 0.08206 L*atm/K*mol

⇒ with T = the temperature = 26 °C = 299 Kelvin

n = (8163*0.860)/(0.08206*299)

n = 0.2861 moles of gas

Step 5: Calculate the mass of air in an air-filled tire.

Mass = moles * molar mass

Mass = (0.2861 moles of gas) (28.8 g/mol)

Mass = 8.24 grams

Step 6: Calculate the mass of helium in a helium- filled tire.

mass of helium = 0.2861 moles of gas * 4 g/mol)

mass of helium = 1.14 grams

Step 7: What is the mass difference between the two?

Δmass= 8.24 grams - 1.14 grams

Δmass= 7.10 grams

8 0

4 years ago

The difference in composition between a weak base and its conjugate acid is

Svetach [21]

A weak Bronsted-Lowry base is a weak proton acceptor, where the proton is in the form of H+, so the conjugate acid formed contains one more H atom and an extra positive charge.
Hope this helps!

3 0

3 years ago

Draw the structure of 4-methyl-5-oxohexanal.

aniked [119]

Answer:

Explanation:

The structural formula provides more information which is often used to represent a particular organic substance. A structural formula indicates how the atoms are arranged within the molecule of a substance. From the information, the structure of 4-methyl-5-oxohexanal is represented by using a stick formula where the methyl group falls into position 4 and oxygen group falls into position 5 on the hexanal compound.

The structure is provided in the image attached below for better understanding.

4 0

4 years ago