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15 points

Answer:

Microscopes and telescopes often use two lenses to make an image large enough to see. A compound microscope uses two lenses to achieve high magnification. Both lenses are convex, or converging. Light from the object first passes through the objective lens.

Explanation:

A compound microscope uses two lenses to achieve high magnification

Answer: it's 4nitrogen

denotes two nitrogen atoms. 2. N 2 denotes one molecule of nitrogen gas.

Explanation:

Answer:

1.sodium chloride

Explanation:

because the others dont have all the listed properties

Answer:

13. 2g

14. 5000mL

15. 104,000m

16. 160mm

17. 5600000mg

18. 10hs

19. 0.250km

20. 1daL

Explanation:

13. 1000milligram (mg) = 1gram (g)

Hence, 2000mg = 2000/1000

= 2g

14. 1 litre (L) = 1000millilitre (mL)

Hence, 5L = 5 × 1000

= 5000mL.

15. 1kilometre (km) = 1000metre (m)

Hence, 104km = 104 × 1000

= 104,000m

16. 1 centimetre (cm) = 10millimeters (mm)

Hence, 16cm = 16 × 10

= 160mm

17. 1kilogram (kg) = 1000000 milligram (mg)

Hence, 5.6kg = 5.6 × 1000000

= 5600000mg

18. 1 second (s) = 0.01 hectosecond (hs)

Hence, 1000s = 1000 × 0.01

= 10hs

19. 1000metre (m) = 1kilometre (km)

Hence, 250m = 250/1000

= 0.250km

20. 1 centiliter (cl) = 0.001 Decaliter (daL)

Hence, 1000cl = 1000 × 0.001

= 1daL

Answer:

Hate to take up this answer spot, but there is no statements about phase changes.

Here are some phase changes to help: when matter changes phase.  Most common ex. is water(liquid) to ice(solid).  It is created by particles coming together, or spreading apart.

Brainliest?

Answer:

[tex]n_{FeS}=0.686molFeS \\\\n_{H_2S}=23.3gH_2S[/tex]

Explanation:

Hello!

In this case, according to the given chemical reaction, it is possible to apply the following stoichiometric setups in order to compute the moles of reacting FeS and the grams of produced H2S, given the mass of HCl (molar mass = 36.46 g/mol) as shown below:

[tex]n_{FeS}=50.0gHCl*\frac{1molHCl}{36.46gHCl}*\frac{1molFeS}{2molHCl}\\\\n_{FeS}=0.686molFeS \\\\\\m_{H_2S}=50.0gHCl*\frac{1molHCl}{36.46gHCl}*\frac{1molH_2S}{2molHCl}*\frac{34.04gH_2S}{1molH_2S} \\\\n_{H_2S}=23.3gH_2S[/tex]

Best regards!

0.044 mol CaOH

Math

Pre-Algebra

Order of Operations: BPEMDAS

Chemistry

Atomic Structure

Stoichiometry

Step 1: Define

2.5 g CaOH

Step 2: Identify Conversions

[PT] Molar Mass of Ca - 40.08 g/mol

[PT] Molar Mass of O - 16.00 g/mol

[PT] Molar Mass of H - 1.01 g/mol

Molar Mass of CaOH - 40.08 + 16.00 + 1.01 = 57.09 g/mol

Step 3: Convert

Step 4: Check

Follow sig fig rules and round. We are given 2 sig figs.

0.043791 mol CaOH ≈ 0.044 mol CaOH

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Answer:

How long By Charlie Puth

Answer:

8 × 10³ mol N₂

Explanation:

Step 1: Write the balanced equation

2 C₃H₅N₃O₉ ⇒ 6 CO₂ + 5 H₂O + 0.5 O₂ + 3 N₂

Step 2: Convert the mass of C₃H₅N₃O₉ from tons to grams

We will use the conversion factor 1 t = 907185 g.

1.320 t × 907185 g/1 t = 1.197 × 10⁶ g

Step 3: Calculate the moles corresponding to 1.197 × 10⁶ g of C₃H₅N₃O₉

The molar mass of C₃H₅N₃O₉ is 227 g/mol.

1.197 × 10⁶ g × 1 mol/227 g = 5.27 × 10³ mol

Step 4: Calculate the moles of N₂ formed from 5.27 × 10³ moles of C₃H₅N₃O₉

The molar ratio of C₃H₅N₃O₉ to N₂ is 2:3.

5.27 × 10³ mol C₃H₅N₃O₉ × 3 mol N₂/2 mol C₃H₅N₃O₉ = 7.91 × 10³ mol N₂ ≈ 8 × 10³ mol N₂

Answer: The student observed only one liquid phase because The student removed the aqueous layer instead of the organic layer and then added organic solvent to more organic layer. Diethyl ether is less dense than water.

Explanation:

In organic chemistry, which is the chemistry of carbon atoms, liquid-liquid extraction techniques are used to separate solutes from its crude reaction mixtures. An example of liquid- liquid extraction technique used is the Separatory funnel.

The Separatory funnel extraction technique allows the separation of solutes based on their solubilities in two immiscible liquids. This appears as two phases or layers with the organic solvent on top while the aqueous solution is below the funnel. This is because the organic solvents are less dense than the aqueous solution.

From the question, the student had a dissolved organic compound in an aqueous solution and was given an organic solvent, diethyl ether for its extraction. When the first 10ml of ether was added, the dissolved organic compound mixed with it and remained in the top layer of the mixture. The student removes the lower layer after the first extraction and adds the second 10mL portion of ether to the upper layer remaining in the separatory funnel. After shaking the funnel, the student observes only one liquid phase with no interface because more organic solvent was added to the organic layer that remained after the aqueous layer was removed.

Using Avogrado's constant (6.022e23):

4(6.022e23) = 2.41e24

Answer:

The group number in the periodic table represents number of valence electrons of the elements in a certain group.

Explanation:

There are s, p, d, and f blocks, which you can see in periodic table

The s-block and p-block together are usually considered main-group elements, the d-block corresponds to the transition metals, and the f-block encompasses nearly all of the lanthanides (like lanthanum) and the actinides (like actinium)

There are three main principles, which may useful for you:

Hope this helps!

The question is incomplete, the complete question is;

In a laboratory experiment, students synthesized a new compound and found that when 12.23 grams of the compound were dissolved to make 228.1 mL of a benzene solution, the osmotic pressure generated was 4.55 atm at 298 K. The compound was also found to be non-volatile and a non-electrolyte. What is the molecular weight they determined for this compound?

Answer:

287.76 g/mol

Explanation:

From;

π = M R T

M = molarity

R= gas constant

T = temperature

number of moles = π * volume/RT

number of moles = 4.55 * 228.1/1000/0.082 * 298

number of moles = 1.037855/24.436

number of moles = 0.0425 moles

Molar mass = mass/number of moles

Molar mass = 12.23 grams/0.0425 moles

Molar mass = 287.76 g/mol

Answer:

I cant see it that well but id be happy to help if u post a clearer picture!

Explanation:

Answer:

4 orbits in the fourth period.

19 electrons in the atom from group 1 and fourth period.

Explanation:

Potassium has 19 electrons distributed in its 4 orbits

The number of periods in a periodic table, tells the number of shells or orbitals of the atoms in that row in which the electrons are filled. Thus the fourth period elements have 4 orbitals and the first element in group one of the fourth period is potassium containing 19 electrons.

All elements in a periodic table are classified into different groups and periods. The vertical columns in the periodic table is called groups and the horizontal rows are called periods.

A group contains elements with same number of valence electrons and similar physical and chemical properties. In a period from left to right the atomic number increases but the number of orbitals in which the electrons are filled will be the same.

Down a group the number of orbitals increases by one. Thus, each elements contains electrons in an increment of 8, 18, 18 and 32 down a group. Thus, from third period to fourth period the number of orbital increases to 4.

The number of electrons will be +8 from the previous element in the group in third period. Thus, below sodium (11) the first element in fourth period is potassium with 19 electrons.

To find more on periodic table, refer here:

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Answer:

The bending of light as it passes from one medium to another is called refraction

Explanation:

Answer: 310.7 grams

Explanation:

Multiply the two values so the units of mL cancel and you get grams

2.545*122.1 = 310.7 grams

Answer:

a. the width of region 2 would be smaller

If the same reaction was shown without a catalyst, the height of region 2 would be larger, so the correct option is (C).

A catalyst is a substance that speeds up the rate of a chemical reaction without being consumed in the process. It works by providing an alternate pathway for the reaction with a lower activation energy, making it easier for the reactants to transform into products.

Catalysts can be solids, liquids, or gases, and they can be homogeneous or heterogeneous, depending on whether they are in the same phase as the reactants or in a different phase.

Catalysts are widely used in many industrial processes, such as the production of fertilizers, plastics, and fuels, to increase the efficiency and reduce the cost of the reaction. They can also be found in biological systems, where they play a crucial role in metabolic processes, such as the breakdown of food in the digestive system or the conversion of light into chemical energy in photosynthesis.

Learn more about catalyst, here:

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Answer:

Continuing on across the periodic table we see that fluorine is the next element after oxygen. ... Rather than forming seven bonds fluorine only forms a single bond for basically the same reasons that oxygen only forms two bonds. Hydrogen fluoride, HF, has one bond, but four centers of electron density around the fluorine.

Answer:B

Explanation:

Maybe

Answer:B is correct

Explanation:

Answer:

Zero

Explanation:

Answer:

Tt

Explanation:

T= Dominant tall

t= non-dominant short.

Dominant always shows over non-dominant.

Answer:

6.499 g

Explanation:

One part of the aqueous HBr reacted with Zinc Hydroxide following the reaction:

And the remaining HBr reacted with NaOH:

First we calculate how many HBr moles remained after reacting with Zn(OH)₂. That number equals the number of NaOH moles used in the titration:

Now we calculate how many moles of HBr reacted with Zn(OH)₂:

Then we convert those 130.75 mmoles of HBr to the Zn(OH)₂ moles they reacted with:

Finally we convert Zn(OH)₂ moles to grams:

Answer:

4d orbital.

Explanation:

Hello!

In this case, since zirconium's atomic number is 40, we fill in the electron configuration up to 40 as shown below:

[tex]1s^2,2s^2,2p^6, 3s^2,3p^6,4s^2,3d^{10},4p^6,5s^2,4d^2[/tex]

Thus, the orbital 4d is partially filled.

Best regards!

Answer:

3rd

Explanation: