Answer:
2NaNO3+1PbO=1Pb(NO3)2+1Na2O
Explanation:
My chem teacher always had us make a T-chart for products and reactants on both sides to help you figure out balancing equations
Conservation of mass is the underlying principle of balancing equation. When we balance equation, this means that we acknowledge that before and after the chemical reaction, the elements are conserved. To balance the chemical equation, we add coefficients before each reactant and product. Here are the following answers:
Reaction 1:
<span>2Al
3ZnCl2
3Zn
2AlCl3
Reaction 2:
</span><span>4NH3
3O2
2N2
6H2O</span>
Answer : B) In step 2, there was a chemical change which was observed in sugar.
Explanation : In A step 2 there was a physical change that was seen. By just boiling the dissolved salt solution salt was obtained. Therefore, it is a physical change. In B step 2 there was a chemical change seen as sugar solution was thickened and turned brown. It was not obtained in its original form; there was a chemical reaction that took place during sugar evaporation. As chemical change is the one where the reaction is irreversible.
Therefore only in B step 2 there was a chemical change that was observed.
Answer : The correct option is, Subscript numbers tell us how many of the element to their upper-left there are in the molecule.
Explanation :
Subscript number : It indicates that the total number of atoms of an element present in a molecule.
While witting a chemical formula, first we have to write the symbol of an element and then write the number in the bottom of the symbol.
For example :
is the chemical formula of the glucose molecule. The glucose molecule is made up of six carbon atoms, twelve hydrogen atoms and 6 oxygen atoms.
The number 6 of carbon atom is written after and in the bottom (lower-right) of the symbol of carbon element (C). Similarly, the number 12 is written lower-right of the symbol of hydrogen element (H) and the number 6 is written lower-right of the symbol of oxygen element (O).
Therefore, the subscript numbers tell us how many of the element to their upper-left there are in the molecule.
Answer:
Tell your teacher or learning coach.
Explanation:
It is always best to let an experienced teacher or coach know what has happened, so they may address it carefully and correctly.
Hope this helps : )
