Answer: the train was going 25 mph
Explanation: 100 divided by 4 is 25
Alkaline earth metal are the elements present in II group in the periodic table and are known as 'Metals' and have a charge of +2.
Alkaline earth metals - Be , Mg Ca, Sr , Ba, Ra
Halogens are present in VII A group in the periodic table and are 'Non-metals' and have a charge of -1.
Halogens - F, Cl, Br, I, At
When Alkaline earth metal (metals) combine with Halogens (non-metals) the compound formed will be ionic compound and the formula of the compound will be based on the charges of the element.
When we write the formula of the ionic compound the charges of the elements get criss crossed.
For example - Mg (Alkaline earth metal) have a charge of +2 and Cl (Halogen) have a charge of -1 and when they combine to form the formula their charges get criss crossed and we will get
or 
When an alkaline earth metal, A, reacts with a halogen, X, the formula of the Ionic compound formed should be 
Answer:
Al(C2H3O2)3 (aq) + 3AgNO3 (aq) ------>Al(NO3)3(aq) + 3Ag(C2H3O2)(s)
Explanation:
A chemical reaction refers to an interaction between two or more chemical species that leads to the formation of other new chemical species.
There are many types of chemical reactions. The type shown above is called a double replacement reaction. In this type of reaction, ions exchange partners in the product.
A chemical reaction is said to be balanced when the number of atoms of each element on the left hand and right hand sides of the reaction equation are exactly the same.
All scientists try to base their conclusions on data and measurements.