Which of these elements exist as a liquid at normal earth temperatures? select all that apply. bromine sodium oxygen mercury

Explanation:

Normal Earth temperature means the standard temperature and pressure conditions. At STP, temperature is 273 K or zero degree celsius and pressure is 1 atm.

For gases at STP, volume is equal to 22.4 liter.

So, at normal Earth temperature sodium exists as a solid whereas oxygen exists as a gas.

On the other hand, both bromine and mercury exists as liquid at normal Earth temperature.

the atomic number will stay the same no matter how many electrons it has, so it doesn’t decrease nor increase. it’ll only change with a different number of protons

answer : one can design an experiment using a liquid and an additive that can be added to the liquid and observe the chemical changes in the reaction species.

one would need a beaker which is filled with a known amount of the liquid in which thermometer is placed to measure the temperature changes; after addition of the additive to the liquid solution one can note down the temperature change and find whether the reaction is endothermic or exothermic in nature. by subtracting the initial temperature value with the final temperature one can find the temperature changes.

various combinations of liquid and additive can be used. liquid in this case can be a known quantity of water and additives can be epsom salt or without epsom salt the experiment can be conducted to notice the changes. water and ice, hydrogen peroxide and dry yeast, vinegar and baking soda,etc.