If I have 2.4g of magnesium, how many g of oxygen(O2 ) will I need to react completely with the magnesium? 2Mg +O2 → MgO

How to find how many electrons are in an element

Murljashka [212]

Explanation:

1) Locate the atomic number in the upper left corner of the square. The atomic number will tell you the number of protons

2) In a neutral state, the element will contain the same number of protons as it will electrons.

--> Boron (B) has an atomic number of 5, so it has 5 protons.

--> Having 5 protons (+1 charge each) means to be balanced, it must have 5 electrons (-1 charge each)

However, what if it's not in a neutral state?

If it's not in a neutral state, it will look something like this:

Ca ^ 2+

<em>Btw, the "^" means that it will be written like it's an exponent. That confuses people sometimes.</em>

Anyways, the "2+" means it's an ion with a positive charge of 2. For us to have a positive charge, it means it's lost two electrons (cause electrons are negative, so taking them away means we are left with a more positive charge).

To get the number of remaining electrons, subtract the 2 from the atomic mass. In this case, that would be 20.

20 - 2 = 18 electrons

Another example:

N ^3-

Atomic Number: 7

7 + 3 = 10 electrons.

Why did I add here instead of subtracting? It's cause the 3- means we have added electrons, resulting in the ion having a negative charge. It's got more electrons than usual.

Hopefully this helps a bit.

5 0

3 years ago

The dissolution of ammonium nitrate occurs spontaneously in water at 25°C. As NH4NO, dissolves, the temperature of the water dec

MA_775_DIABLO [31]

Answer:

ΔG <0 , ΔH > 0 , ΔS > 0 .

Explanation:

From the data given in question , the reaction is a spontaneous process , hence , the value of change in gibbs free energy would be negative , ΔG <0

And , on dissolution process , the temperature of the water decreases , i.e. , it is an endothermic process , i.e. , the change in enthalphy value is positive , ΔH > 0

And , during the process of dissolution , the ammonia salt break does to ions , i.e. , the randomness increases , hence the ΔS > 0

6 0

4 years ago

The Society of Automotive Engineers has established an accepted numerical scale to measure the viscosity of motor oil. For examp

natta225 [31]

Answer:

Most viscous to least viscous: $(c)> (b)> (a)$

Explanation:

For hydrocarbons, viscosity increases with increasing molar mass. Because increasing molar mass signifies increase in number of electrons in molecules.

We know that in non-polar hydrocarbons, only van der waal intermolecular force exists. Van der waal force is proportional to number of electrons in a molecule.

Therefore with increasing molar mass, van der waal force increases. hence molecules gets more tightly bind with each other resulting increase in viscosity.

Here molar mass order : $(c)> (b)> (a)$

Therefore viscosity order : $(c)> (b)> (a)$

5 0

4 years ago

What is true of a gas

velikii [3]

Answer:

did you have options, cause if you did chose something alond the lines of

Explanation:

A real gas is a gas that does not behave as an ideal gas due to interactions between gas molecules. A real gas is also known as a nonideal gas because the behavior of a real gas in only approximated by the ideal gas law.

3 0

3 years ago

You are building a uniform to protect workers from all types of nuclear radiation. If you use material that blocks _____ radiati

defon

A. Gamma radiation because it reaches further than beta and alpha rays

8 0

3 years ago