Group 1A (the alkali metals) almost always form cations (positive ions). They'd need anions (negative ions) to ionic bond with. Beryllium (Be) is group 1A already and forms Be+ cation. Bromine is a halogen, and forms Br-, an anion. Platinum is a metal, and usually won't ionic bond with anything. Francium is rare and highly radioactive, plus it so happens to be group 1A as well. Only bromine can form the anion that the group 1A cations need.
Answer: try to understand coz the question is not valid
Explanation: Explain the relationship between forward and reverse reactions at equilibrium and predict how changing the amount of a reactant or product (creating a stress) will affect that relationship.For example (select one from each underlined section)If the amount of (reactant or product) increases, the rate of the (forward or reverse)reaction will (increase or decrease)to reach a new equilibrium. If the amount of (reactant or product) decreases, the rate of the (forward or reverse)reaction will (increase or decrease)to reach a new equilibrium. Procedure: Access the virtual lab and complete the inquiry experiment
The empirical formula of this compound is 
<h3>Empirical formula </h3>
To calculate the empirical formula of a compound, the value of moles of each element is needed.
As we have the information of the mass value, we will use the molar mass expression, which corresponds to:





As the value of the empirical formula must be an integer, simply multiply the two values by a common factor:


So, the empirical formula of this compound is
.
Learn more about empirical formula: brainly.com/question/1247523
Answer:

Explanation:
Hello,
In this case, since silver is initially hot as it cools down, the heat it loses is gained by the liquid, which can be thermodynamically represented by:

That in terms of the heat capacities, masses and temperature changes turns out:

Since no phase change is happening. Thus, solving for the heat capacity of the liquid we obtain:

Best regards.