An atom of aluminum has 13 protons and 14 neutrons. what is the atomic mass

What is the electronic configuration of Au3+?

Anettt [7]

Answer:

$AU^{3+} : [Rn] 5f^3$

Explanation:

Writing electronic configuration of any element you should know atomic number of that element ,

and also electrons are filling according to their energy level and first electron is filled in the lower energy orbital

and it follows n+1 rule if n+1 is same for two orbital electron will go first in the lowest value of n.

writing electronic configuration of ion can be done like first for their neutral atom and then add or remove electron it will make things easy because there are also some eception case their you may do wrong.

$AU : [Rn] 5f^3 6d^1 7s^2$

remove three electron from outer most shell of AU

$AU^{3+} : [Rn] 5f^3$

4 0

3 years ago

How would you test a colorless crystalline compound to determine if it was a hydrate?

Cloud [144]

A hydrate is a substance where in it contains water and other constituent elements. To know whether if that compound was a hydrate,you should record its mass, then put it in a test tube and heat it with a Bunsen burner. If the compound is a hydrate, the water in the compound will discharge in the form of water vapor. At the next 5-10 minutes, remove it in the test tube and weigh it up again. If the mass is now fewer, that means that there was water existing that has now evaporated, and the compound was a hydrate.

6 0

3 years ago

If 16.0 mL of acetone is dissolved in water to make 155 mL of solution what is the concentration expressed in volume/volume % of

Lady_Fox [76]

Percentage by volume of solution is the percentage volume of solute in total volume of solution.
Volume percentage (v/v%) = volume of solute / total volume of solution x 100%
volume of solute - 16.0 mL
total volume of solution - 155 mL
v/v% = 16.0 / 155 x 100% = 10.32%
this means that in a volume of 100 mL solution, 10.32 mL is acetone.

7 0

2 years ago

Gizmo Warm-up

Mariana [72]

Sodium hydroxide solution and hydrogen gas are produced from the reaction of water and sodium.

<h2>Reaction of sodium and water</h2>

We observe bubbles coming out of the water when the sodium reacts with the water because of the formation of hydrogen gas which is insoluble in water so it moves into the atmosphere.

<h3>Products of the reaction</h3>

Sodium metal reacts rapidly with water to form sodium hydroxide (NaOH) solution and hydrogen gas (H2). This chemical reaction is exothermic because huge amount of heat is release from the solution so we can conclude that sodium hydroxide solution and hydrogen gas are produced from the reaction of water and sodium.

Learn more about chemical reaction here: brainly.com/question/26018275

Learn more: brainly.com/question/26167984

8 0

1 year ago

If 8.00 g NH4NO3 is dissolved in 1000 g of water, the water decreases in temperature from 21.00 degrees Celsius to 20.39 degrees

telo118 [61]

Answer:

25.7 kJ/mol

Explanation:

There are two heats involved.

heat of solution of NH₄NO₃ + heat from water = 0

q₁ + q₂ = 0

n = moles of NH₄NO₃ = 8.00 g NH₄NO₃ × 1 mol NH₄NO₃/80.0 g NH₄NO₃

∴ n = 0.100 mol NH₄NO₃

q₁ = n * ΔHsoln = 0.100 mol * ΔHsoln

m = mass of solution = 1000.0 g + 8.00 g = 1008.0 g

q₂ = mcΔT = 58.0 g × 4.184 J°C⁻¹ g⁻¹ × ((20.39-21)°C) = -2570.19 J

q₁ + q₂ = 0.100 mol ×ΔHsoln – 2570.19 J = 0

ΔHsoln = +2570.19 J /0.100 mol = +25702 J/mol = +25.7 kJ/mol

7 0

3 years ago