12. A student set up an experiment to investigate substances formed when a candle burns in air utute
7
To pump
Calcium hydroxide
Ice cold water
candle
a) What observation was made in the;
U-tube
Boiling tube containing calcium hydroxide

if you mean hydrogen and oxygen then water is the product

explanation:

let the different atoms be x and y. each with four protons and same mass will be represented as follows.

mass number is number of protons + number of neutrons.

            and  

since, it is given that one has a negative charge while the other is neutral. therefore, there will be increase in number of protons and the atom will be represented as follows.

according to periodic table, mass number of beryllium is 9 and it has atomic number 4 so, the atoms will be and .  

the protons and neutrons will be located inside the nucleus whereas the electrons will be revolving around the nucleus.  

aquifers are bounded above and below by impermeable rock. the driving force of groundwater movement in confined aquifers is pressure, rather than gravity.