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exis [7]
3 years ago
15

20. When the hydrogen supply in the core begins to run out, and the star is no longer generating heat by nuclear fusion, the cor

e becomes unstable and contracts. The outer shellof the star, which is still mostly hydrogen, starts to expand. At this phase the star is called a _____.
a.White dwarf
b.Red dwarf
c.Red Giant
d.Black hole
Chemistry
1 answer:
Triss [41]3 years ago
5 0

Answer:

b

Explanation:

i seached it up

You might be interested in
Water boils at 100°C at sea level. If the water in this experiment did not boil at 100°C, what could be the reason?
RSB [31]
One reason could be that the water in this experiment, didn’t boil, but instead became a “chemical reaction” from atmospheric pressure which is normal.

While heating two different samples, of
sea level water it decides on a temperature of 102°C and the other boils at 99.2°C. Basically calculating of the percent error.
6 0
3 years ago
A 1.0 mol sample of which of the following compounds has the greatest mass?
Sholpan [36]

Answer:

D) N2O5

Explanation:

The molar mass of a substance is defined as the mass of this substance in 1 mol. To solve this question we must find the molar mass of each option:

<em>Molar mass NO:</em>

1N = 14g/mol*1

1O = 16g/mol*1

14+16 = 30g/mol

<em>Molar mass NO2:</em>

1N = 14g/mol*1

2O = 16g/mol*2

14+32 = 46g/mol

<em>Molar mass N2O:</em>

2N = 14g/mol*2

1O = 16g/mol*1

28+16 = 44g/mol

<em>Molar mass N2O5:</em>

2N = 14g/mol*2

5O = 16g/mol*5

28+80 = 108g/mol

That means the compound with the greatest mass is:

<h3>D) N2O5</h3>
5 0
3 years ago
Which one of the following classes of organic compound does not contain the carbonyl (C=O) group?A) aldehydesB) carboxylic acids
vredina [299]

Answer: alcohols

Explanation:

The carbonyl group refers to C=O. It is contained in aldehyde, Ketones, carboxylic acids , esters, amides and acyl chlorides. They are not found in alcohols. The alchols are generally ROH. They do not contain any carbon-oxygen unsaturated bond in their structure hence the answer.

3 0
3 years ago
1. How many moles of nitrogen gas are in 1.54x10^26 molecules? How many atoms?
kow [346]

Answer:

Try everything

1. How many moles of nitrogen gas are in 1.54x10^26 molecules? How many atoms?

2. How many molecules of water are in 3.45 moles of water?

3. How many atoms of C are in 2.00 moles of Cv6Hv12Ov6? (v means the number is below)

Explanation:

6 0
3 years ago
For a voltaic cell consisting of Al(s) in Al(NO3)3(aq) and Cu(s) in Cu(NO3)2(aq), what is Ecell, given [Al3 ]
xz_007 [3.2K]

Answer:

2.0 V

Explanation:

For the oxidation half cell;

Al(s) -------> Al^3+(aq) + 3e.

For reduction half cell;

Cu^2+(aq) +2e ------> Cu(s).

E°cell = E°cathode - E°anode

But;

E°cathode= 0.34 V

E°anode = -1.66 V

E°cell= 0.34 -(-1.66)

E°cell= 2.0 V

5 0
4 years ago
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