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Natali5045456 [20]

2 years ago

15

When silver coins are found in ancient shipwrecks,they are coated with a black crust. What question could you ask to help you de

cide whether the silver underwent a chemical change or a physical change? Explain.

1 answer:

leonid [27]2 years ago

8 0

It went under a physical change because it (1) changed color. (2) changed form.

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You believe you have cracked a secret code that uses elemental symbols to spell words. The code uses numbers to designate the el

Stells [14]

Explanation:

Atomic numbers for neutral atoms are the same as the number of electrons. The number of electrons are used in writing the subshell notation where we can see the highest princpal quantum number(n).

In order to solve this problem, a good knowledge of the periodic table and shell notation is required.

For example;

Given a number 5;

We know the number is made of both the atomic number of the element and the highest quantum number.

It is easier for us to know the highest quantum number from the shell notation:

shell notation 1s²2s²2p¹

highest principal quantum number is 2

We are left with atomic number 5-2, which is 3

The element is therefore Li.

Part A. 5, 30, 58, 56, 99, 79, 19, 98, 9

Li Fe I Sb U Ta S Pa N

Part B. 9, 99, 30, 95, 19, 47, 79

N U Fe Ra S Mo Ta

Learn more:

s-orbital brainly.com/question/9288609

#learnwithBrainly

4 0

3 years ago

An element or compound which occurs naturally in the earth is a ___?

Rzqust [24]

An element or compound which occurs naturally in the earth is a mineral

5 0

2 years ago

Read 2 more answers

Concentrated hydrochloric acid, HCl, comes with an approximate molar concentration of 12.1 M. If you are instructed to prepare 3

Semmy [17]

Answer:

28.20 mL of the stock solution.

Explanation:

Data obtained from the question include the following:

Molarity of stock solution (M1) = 12.1 M

Volume of diluted solution (V2) = 350.0 mL

Molarity of diluted solution (M2) = 0.975 M

Volume of stock solution needed (V1) =..?

The volume of stock solution needed can be obtained by using the dilution formula as shown below:

M1V1 = M2V2

12.1 x V1 = 0.975 x 350

Divide both side by 12.1

V1 = (0.975 x 350)/12.1

V1 = 28.20 mL.

Therefore, 28.20 mL of the stock solution will be needed to prepare 350.0 mL of 0.975 M HCl solution.

6 0

2 years ago

Can someone please help me with this!!!<br><br> ( I chose to stop using water bottles )

Dafna1 [17]

Answer:

Flushing goldfish down the toliet

Explanation:

This would help the planet because goldfish are a very evasive species that has been harming our natural enviroments lakes and rivers. Ever since people have been flushing them down the toliet including me since I've had over six they have been finding their ways into our ecosytem and damaging nature. You may think that goldfish are a cute and small pet species to keep in a fish tank but the fish can grow in the right conditons up to 16.1 inches long and can top over five pounds in the wild. Unfortunately most goldfish never thrive like this in fish tanks due to nasty inadequate housing and feeding conditions. And most do not live up to their expected life span in the wild of 15 to even thirty years due to their living conditons. Did you know, goldfish will actually jump out of their tank in a final desperate search for better living conditions and enviroment to live in to meet their physiological needs. But lets get back to the problem so don't be to quick to feel sorry for them, when people flush them down the toliet they repopulate somehow in our lakes and rivers. Even through, it is not clear how they got there, which the suspected culprit is the sewer system. They threaten the natural enviroment tho because they are obnivores and they eat a mixtures of plants and animal specimen. You are probrably thinking why is this a problem, well its because goldfish are particullary greedy eaters and will eat, eat, and feast on the natural envrioment they infestated. And the waste they leave on the enviroment will promote the growth of algae which could cause an extent of enviromental damage. Of course goldfish are not impacted by this algae growth for adaptation reasons which shield them. This is not the main problem tho the main problem of this is that female goldfish can produce up to 1000 eggs at a time. And to make things worse unlike other fish species where the parents of the eggs leave the eggs for predaetors and well the elements of nature the goldfish instead guard their nest foriciously from predaetors that eat fish eggs in which effectively shields the populations young from danger. And to just add to the chaos the goldfish sadly have no real natural predaetor in the unitedstates which just causes more problems since they have no one killing them. And did I mention that they could live up to a real possibility of thirty years. And that they are forocious eaters that could eat a variety of types of foods. All of these facts in the end lead to two things first stop flushing your pet goldfish down the toliet and secondly now you know how golfish impact our planet.

Give brainliest please it took me over thirty minutes of thinking!

4 0

2 years ago

What are the parts of a chromosome

juin [17]

Answer:

the centromere, the arm and the telomere

Explanation:

3 0

2 years ago