<span> First you need to know how many isotopes there are of silicon, and its average atomic units (look at periodic table). Then make up a system of equations to solve for it. Theres 3 stable silicon isotopes (28, 29, 30) so you will need to have 3 equations. You must be given the percent abundance of at least one of the isotopes to solve because here I can only see 2 equations (numbered down below) set x = percent abundance of si-28 y = percent abundance of si-29 z = percent abundance of si-30 since all of silicon atoms account for 100% of all silicon: x + y + z = 100% = 1 therefore: 1) x = 1 - y - z You also have 2) 28x + 29y + 30z = average atomic mass you can substitute x so that equation becomes: 28 (1 - y - z) + 29y + 30z = average atomic mass See how you have 2 variables here? You cant go on until you know the value of one isotope already or you have given a clue which you can derive the third equation</span>
Hey there!
The correct answer to your question is a compound.
A substance of two or more elements chemically combined in a set ratio, or proportion, is called a compound.
This is because compounds are made of two or more elements. Table salt is an example of a compound because it is made up of the elements chlorine and sodium.
Hope this helps you.
Have a great day!
Answer:
They are in a periodic table
<h3>
Answer:</h3>
Reactivity increases because the valence level is further from the nucleus of an atom.
<h3>
Explanation:</h3>
- The reactivity of elements in the periodic table depends on the position of the element in the periodic table.
- The trend in the reactivity across the period and down the group depends on whether one is dealing with metallic elements or non-metallic elements.
- Reactivity of metals such as alkali metals and alkali-earth metals increases down the group as the number of energy levels increases making valence electrons to be further from the nucleus.
- Reactivity of non-metallic groups such as halogen decreases down the group as energy levels increase which reduces the nuclear attraction of the valence electrons to the nucleus.
Answer:
13.36
first you have to convert the grams of nitrogen into moles when you got the moles of nitrogen. Then 2 moles of ammonia react with 1 mole nitrogen you have doubled the nitrogen mole and then convert the moles into the grams of ammonia.
use this formula for that:
moles = gram/molar mass
