Stars are _____
for most of their lives.
A) stable
B) unstable
C) unpredictable

[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:

Answer: mountains not sure

Water is chemical

Box is physical

Lion is physical

Hope this helped!!

Explanation:

Answer:

A

Explanation:

Density: water>ice>methanol

Ice is lighter than methanol hence it is able to float on it. However, ice is denser than water hence it sinks.

Answer:

The answer is A.

Explanation:

The density of ice in methanol must be different from that in water.

Answer:

The statements that accurately  describe how the assumptions affects scientific thinking are;

People think that the Earth is flat, so they think that it is only safe to travel certain distances from a given location.

People think that the Earth is flat, so think that when the Sun sets, it does underneath the Earth

Explanation:

The proof that the Earth is round was made by the Greek philosopher, Aristotle, over 2,000 years ago, by observation of the change in the constellation of the stars as a person changes his position North or South

The initial belief was that the Earth is flat disc surrounded by water, while the it was believed that the shape of the Earth was that of a square with four mountains at the vertices that support the sky from falling.

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:

4.36g XY

I hope it helps!

Answer:

for number 2

Explanation:

Hydrogen. Hydrogen ignites in air. If hydrogen is present in a test tube, a lighted splint held near its mouth ignites with a squeaky pop.

Explanation:

this may help u follow me and mark as brainlist PlZzzzz

Answer:

Solar Eclipse happens when the moon gets between the sun and the earth, the moon gets all the light and blocks the earth from getting sunlight.

Hope this helps ;) ❤❤❤

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

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

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)