In a neutral atom, the number of protons is equal to the number of electrons.
Given that the charge on the ion of the element is -1. This means that there is one electron more than the number of protons in the element.
The atomic number = Number of protons = 57 -1 = 56
Element with atomic number 56 is Barium.
Mass number of the element = Number of protons + Number of neutrons
= 56 + 80 = 136
So the identity of the species: 
Answer : The correct answer is a) an exothermic reaction that releases energy.
Combustion reaction is generally referred as burning or when hydrocarbon reaction with oxygen to produce carbon dioxide and water . Combustion reaction releases energy. Example :
CH₄ + O₂ → CO₂ + H₂O + Energy or heat .
The reaction which releases energy or heat are known as Exothermic reactions .
Since it says hot dogs and hamburgers are cooked means they are undergoing combustion chemical reaction and so they are exothermic reactions. So option a) an exothermic reaction which releases energy is correct .
There are two oxygens on the left side of the equation and three on the right
Transition metals seem to have fairly even levels of reactivity though it seems they to react more with bases than acids. If I didn’t know from the lessons, I would say alkali and alkaline earth metals weren’t very reactive.
(That's my answer when I did a lab about the reaction of metals for chemistry at least.)
Answer:
0.79 g
Explanation:
Let's introduce a strategy needed to solve any similar problem like this:
- Apply the mass conservation law (assuming that this reaction goes 100 % to completion): the total mass of the reactants should be equal to the total mass of the products.
Based on the mass conservation law, we need to identify the reactants first. Our only reactant is sodium bicarbonate, so the total mass of the reactants is:
We have two products formed, sodium carbonate and carbonic acid. This implies that the total mass of the products is:
Apply the law of mass conservation:
Substitute the given variables:
Rearrange for the mass of carbonic acid:
