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Tema [17]
3 years ago
5

Which element has 21 neutrons and 20 electrons?

Chemistry
2 answers:
mario62 [17]3 years ago
6 0
Scandium has 21 neutrons
LuckyWell [14K]3 years ago
4 0

Answer:

Calcium is your answer

Have a good day ahead

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What will be the volume occupied by 2.5 moles of nitrogen gas exerting 1.75 atm of pressure at 475K?
Marina86 [1]

Answer:

THE VOLUME OF THE NITROGEN GAS AT 2.5  MOLES , 1.75 ATM AND 475 K IS 55.64 L

Explanation:

Using the ideal gas equation

PV = nRT

P = 1.75 atm

n = 2.5 moles

T = 475 K

R = 0.082 L atm/mol K

V = unknown

Substituting the variables into the equation we have:

V = nRT / P

V = 2.5 * 0.082 * 475 / 1.75

V = 97.375 / 1.75

V = 55.64 L

The volume of the 2.5 moles of nitrogen gas exerted by 1.75 atm at 475 K is 55.64 L

6 0
3 years ago
How many atoms are in Sodium, Carbon, Hydrogen, Oxygen, Fluorine, Boron, Lithium, Helium, Phosphorus and Sulfur?
vlada-n [284]
Sodium. 11
Carbon. 12
Hydrogen 1
Oxygen 2
Fluuorine. 14
Boron. 5
Lithium. 6
Helium 3
Phosphorus 15
Sulfur 6
6 0
3 years ago
Match the following items.
navik [9.2K]

Answer:

1. not affected by a magnet                      1 liquid

2. mostly space                                          2 solid

3. flows freely but particles still attract 3 proton

4. positively charged particles                  4 gas

5. free to move in all space                       5 alpha particles

6. negatively charged particles                 6 atoms

7. atoms nearly fixed in space                   7 gamma ray                                                    8. helium nucleus                                        8 electron (beta)

6 0
2 years ago
On the seashore pebbles that are rough and uneven become smooth and rounded explain how they become smooth and rounded
Andru [333]
The pebbles become smooth and even because of erosion. the waves from the sea rub against the pebbles this is erosion. x
7 0
3 years ago
. Which of the following is a balanced chemical equation for the synthesis of NaBr from Na and Br2?
topjm [15]

Answer: The correct option is:

2Na+Br_2\rightarrow 2NaBr

Explanation:

In balanced chemical equation , mass of the reactants is always equal to the mass of the products.

2Na+Br_2\rightarrow 2NaBr

This is the balanced equation because on both sides number of sodium and bromine atoms are same.

On the reactant side there are two sodium atoms and two bromine atoms

On the product side there are also two sodium atoms and two bromine atoms in NaBr.

Mass of reactants (here 2Na and Br_2)= Mass of products(here 2NaBr)

2(23u) + 2(79.9u) = 2(23u + 79.9u) = 205 u


3 0
3 years ago
Read 2 more answers
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