A Day in the Kitchen!
This is the story of a seven- year- old boy named Dharvik and his mother, who are always trying to explore things around them and to learn science concepts from their surroundings. One Sunday morning, Dharvik decides to spend his full day with his mother, helping her in the kitchen.
His mom starts her daily kitchen routine by keeping a container filled with milk on a gas burner. While she gets busy preparing breakfast, Dharvik notices that the milk comes out of the container and spills over. He quickly turns off the gas stove and asks his mom about the reason behind the spilled milk. He has never seen water overflow like the milk when heated.
His mom relates the science of spilled over milk with the process called evaporation and tries to explain it to him in simple terms. She mentioned, “When water is being heated or boiled, it gets converted into vapors (a gaseous form of water). These water vapors rise upwards and mix with the air around us. Thus, we don’t see the water getting spilled over [when] boiling. However, on the other side, milk is mainly made up of water and many other substances such as sugar, proteins, and fats, etc. When being heated, the water component of the milk gets converted into vapors as usual but other substances don’t and they form a creamy layer on the top of the milk. This thick creamy layer stops the water vapors [from coming] out of the milk. These vapors then forcefully push the cream & milk to clear their path resulting in spilling over of milk.”
Sometime later, Dharvik’s mom starts to prepare lunch and chops onions. While chopping onions, both of them feel irritated in their eyes and tears start falling continuously.
“Why are we getting tears in our eyes?” Dharvik asked his mom.
His mom answered, “Onions are bulb-shaped vegetables that contain sulfur compounds in them. When we cut onions, the sulfur compounds react with the enzymes present in the onions and form a chemical called Propanethiol S-oxide. This chemical quickly evaporates as soon as it is formed and reaches our eyes. After reaching the eyes, it reacts with the water or liquid already present in our eyes and forms a mild sulphuric acid that can harm our eyes. The sensory nerves connected to the eyes then send signals to the brain about this danger and the brain takes quick action by activating our teary glands. These glands then release tears to throw the acid out of our eyes for their protection.” Dharvik understands the logic and finds it really interesting.
While helping his mom in the kitchen, Dharvik starts feeling hungry and takes a slice of cucumber with some lemon juice on it. As soon as he puts it in his mouth, one of his eyes closes for a moment and he makes a strange facial expression.
Dharvik’s mom told him to notice what he just did! She explained, “There are certain things that are not regularly eaten by us and their extreme taste is not stored in our brain. Something that is sour in taste like lemon juice or tamarind could be one of those tastes When we eat these food items, the brain immediately sends messages to our facial muscles, eyes, and tongue etc. warning us against the extreme and not so regular taste of the food we are eating.”
Mom asked Dharvik to call everyone for lunch. After calling everyone, Dharvik said, “Mom, I could smell the food even when I went to the other room. How is that possible?” This time his mom answered, “To cook food, we have to heat it up. When being heated, some of the molecules from the food (that have a pleasant smell) get evaporated and mix with the air molecules around them. The air molecules along with the food molecules then travel to the nearby places giving you a mouth-watering smell of the food that has been cooked.” Dharvik understands the reason and told his mom that he will study more about this concept in detail.
After having lunch, Dharvik helped his mother in the cleaning process. His mother appreciated his help & encouraged him to look around to find out the answers to all of the questions that come to his mind. Since science is everywhere around us and there are a lot of concepts that can be learned from our e surroundings, we must encourage our kids to view things from a science perspective and find out why things are happening in a certain way. The day was full of learning for Dharvik and he decided to share his knowledge with his friends too.
Challenge Yourself: With the supervision of an adult, gather the following things from your kitchen:
· Vinegar (Solution)
· Baking Soda (Solution)
· Detergent/Dish Soap (Solution)
· Lemon Juice (Solution)
· Turmeric Powder
Add turmeric to all five solutions and observe the color change (if any). What do you observe? Can you find out and identify which of these solutions is acidic or basic by just looking at its color after adding turmeric?