Ice sinks in methanol, but floats on water. From this we can conclude: A The density of ice in methanol must be different from that in water. B The density of water must be less than the density of methanol. C The density of ice must be greater than the density of water. D The density of methanol must be less than the density of water.

Answer:

x contain 9 percent ofcalcium carbonaye

Answer:

It is Physics

because these are all physical components and/or characteristics

-Biology is the study of life

-Earth science is the study of the biosphere we live in

-Astronomy is about space

Answer:

Physics

Explanation:

Physics is the study of motion and force...

Biology is the study of life

Earth Science is wind, water and uk...

Astronomy is about planets and stars

Answer:D. Is the correct answer

Explanation:

Following are the calculation of the lead (Pb) atoms:

Balanced reaction:  

[tex]\bold{3PbO+2NH_3\longrightarrow 3Pb+N2+3H2O}\\\\[/tex]

[tex]\bold{mol\ NH_3 \longrightarrow mol \ Pb \longrightarrow atoms \ Pb}[/tex]

Calculating the number of atoms in Pb that will be generated:

[tex]=5.38 \ mol \ NH_3 \times \frac{3\ mol\ Pb}{2 \ mol NH_3} \times \frac{6.022 \times 10^{23} \times pb}{1 \ mol \ pb}\\\\ = 4.86 \times 10^{24} \ atoms\ in \ Pb\\\\= 4.86 \times 10^{24} \ atoms \\[/tex]

Therefore, the answer is "Option D"

Learn more:

brainly.com/question/21092165

Answer:

Answer: mountains not sure

Water is chemical

Box is physical

Lion is physical

Hope this helped!!

Explanation:

Answer:

pseudocience consists of statements, belief or practices that are claimed to be both scientific and factual but are incompatible with the scientific method.

         Errors

Answer:

4.36g XY

I hope it helps!

[tex] \LARGE{ \boxed{ \rm{ \purple{Required \: answer}}}}[/tex]

☃️ Chemical formulae ➝ [tex]\sf{CaCO_3}[/tex]

How to find?

For solving this question, We need to know how to find moles of solution or any substance if a certain weight is given.

[tex] \boxed{ \sf{No. \: of \: moles = \frac{given \: weight}{molecular \: weight} }}[/tex]

And, Then we need to find the number of molecules which can be found by:

[tex] \large{ \boxed{ \sf{no. \: of \: molecules = N_A \times no. \: of \: moles}}}[/tex]

Here, Na = Avagadro Number (6.022 × 10²³)

☀️ As it is a compund, We considered molecules. Then, we can predict the no. of atoms of elements in one molecule of compound and get the answer.

Solution:

Atomic weight of elements:

❍ Molecular weight of [tex]\sf{CaCO_3}[/tex]

= 40 + 12 + 3 × 16

= 52 + 48

= 100 g/mol

❍ Given weight: 10 g

Then, no. of moles,

⇛ No. of moles = 10 g / 100 g mol‐¹

⇛ No. of moles = 0.1 moles

☄ No. of moles of Calcium carbonate in the given weight = 0.1 moles

Finding no. of molecules,

⇛ No. of molecules of CaCO3 = 0.1 × 6.022 × 10²³

⇛ No. of molecules of CaCO3 = 6.022 × 10²²

Now,

Then, 6.022 × 10²² molecules will have,

= 3 × 6.022 × 10²² atoms of oxygen

= 18.022 × 10²² atoms of oxygen

In more scientific form,

= 1.8022 × 10²³ atoms of oxygen

☄ Hence, Final answer - 1.8022 × 10²³ atoms

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Answer:

a

Explanation:

Activation energy is the minimum amount of energy that must be overcome before a reaction will proceed to product.

In the energy diagram, the thick line represent the uncatalyzed path while the broken line line indicates the catalyzed path.

In the diagram above, the letter between the reactant and the Peak of the diagram gives the activation energy. This letter is a.

Therefore, the activation energy for the uncatalyzed reaction is 'a'.

[tex] \LARGE{ \boxed{ \red{ \rm{Answer}}}}[/tex]

☃️ Chemical formulae ➝ [tex]\sf{Ca_3(PO_4)_2}[/tex]

For solving this question, We need to know how to find moles of solution or any substance if a certain weight is given.

[tex] \boxed{ \sf{No. \: of \: moles = \frac{Given \: weight}{Molecular \: weight} }}[/tex]

Atomic weight of elements:

❍ Molecular weight of [tex]\sf{Ca_3(PO_4)_2}[/tex]

= 3 × 40 + 2 × 31 + 8 × 16

= 120 + 62 + 128

= 310 g/mol

❍ Given weight: 20 g

Then, no. of moles,

⇛ No. of moles = 20 g / 310 g mol‐¹

⇛ No. of moles = 0.0645 moles

⚘ No. of moles of Calcium phospate in the given weight = 0.0645 moles.

━━━━━━━━━━━━━━━━━━━━

Answer:

Explanation:

To find the number of moles in calcium phosphate we use the formula

[tex]n \: = \frac{m}{M} [/tex]

where

n is the number of moles

M is the molar mass

m is the mass of the substance

To find the number of moles we must first find the molar mass

Chemical formula for calcium phosphate is

Ca3( PO4)2

Ca = 40 , P = 31 , O = 16

So the Molar mass of calcium phosphate is

M( Ca3( PO4)2 ) = (20×3) + 2( 31 + (16×4)

= 60 + 2( 31 + 64)

= 60 + 2(95)

= 60 + 190

Molar mass of calcium phosphate =

250g/mol

Mass = 20 g

So we have

[tex]n = \frac{20g}{250g/mol} [/tex]

We have the final answer as

Hope this helps you

Answer:

I got 0.01 moles, hope this helps!

Answer:

Explanation:

1- Cathode 2- copper electrolyte solution usually (CuSO4) 3- Cu half cell 4- bulb (when lighted, shows the current is flowing) 5- Zn half cell 6- Zn electrolyte solution 7- connecting wires 8- anode (Zn) 9-salt bridge

2- the copper-(Cu) electrode is the cathode and the zinc-(Zn) electrode will be the anode. This is because the cathode is negatively charged (while Cu is positively charged, so it attracts) and the anode is positively charged (while Zn will be negative)

3- the electrons flow from the anode, where oxidization takes place, to the cathode, where reduction reactions take place.

That's the best i can do. Hope it helps.

Answer:

Explanation:

• Label all parts (1–9), including the solutions in each beaker and the connecting tube.

1. Copper strip

2. Cu2+(aq) (copper electrolyte solution or copper nitrate)

3. Cathode compartment  

4. Light bulb  

5. Anode compartment  

6. Zn2+ (aq) (zinc electrolyte solution or zinc nitrate)  

7. The connecting wires or the external circuit  

8. Zinc strip  

9. Salt bridge  

• Label which cell is the cathode and which cell is the anode. Include the charge on each strip.

The copper strip is the cathode and the zinc strip is the anode. The anode is positively charged and the cathode is negatively charged. This is because the cathode attracts a positive charge and the anode attracts a negative charge.  

• Show, or describe in detail, the flow of electrons.

The atoms from the zinc strip are oxidized into zinc ions, (the anode is where oxidation occurs). The electrons in the anode then travel through the wire to the copper strip. The electrons then merge with the copper ions in the solution creating copper metal (the cathode is where reduction occurs).  

• Describe what type of electrochemical cell is pictured. Explain how the cell works. Include the oxidation and reduction half-reactions in your explanation.  

This is a voltaic or galvanic cell. It works by using spontaneous oxidation-reduction reaction to generate electricity.  

Zn(s) --- Zn2 + (aq) + 2e-  

Cu2 + (aq) + 2e- --- Cu(s)

Explanation:

Divide the mass of chlorine by the molar mass of cobalt chloride, then multiply by 100.

Molar Mass of Cobalt Chloride.

Mass of Chlorine in Cobalt Chloride.

Percent Composition of Chlorine.

Answer:

acquired/harmful

Explanation:

This type of mutation and exposure will cause indefinite problems.

Answer:

[tex]\boxed{\sf B. \ grams/mole}[/tex]

Explanation:

[tex]\sf The \ molar \ mass \ of \ a \ substance \ is \ the \ mass, \ in \ grams,\ per \ one \ mole.[/tex]

[tex]\displaystyle \sf \frac{grams}{mole}[/tex]

Answer:

B

Explanation:

Grams/mole is correct. Got right on test!

The number of protons define what element we're dealing with.

Answer: The number of protons define what element we're dealing with.

Answer:

formed by burns rises quickly hydorogen

[tex] H_2+\frac12O_2 \longrightarrow H_2O[/tex]

I don't think I need to name the product.

this reaction is very exothermic. so the gases and the flames are very hot, i.e. very lighter (hot air rises) than the normal air. so it rises quickly

Answer:

It also helps them understand how life works. It even helps them predict how new materials will behave. In 1869, Dmitri Mendeleev, a Russian chemist, proposed the periodic law and his first periodic table. He published this periodic table two years later in a textbook, The Principles of Chemistry.

Explanation:

Answer:

Dmitri Mendeleev, To summarize, the periodic table is important because it is organized to provide a great deal of information about elements and how they relate to one another in one easy-to-use reference. The table can be used to predict the properties of elements, even those that have not yet been discovered

Explanation:I have already done this

Answer:

Nothing went well.  

Explanation:

Everything went badly.

Explanation:

this may help u follow me and mark as brainlist PlZzzzz