They should identify the confounding variable.
Some condition that is not examined by the scientist might alter the experiment result. That condition is called confounding variable. If the method of the experiment same but result is very different, there should be unidentified confounding variable. It could be air humidity, temperature, ventilation, light, time of the year or anything that might not be seen by naked eye.
Try to redo the experiment with controlling variable as much as possible.
Probably when u close your eyes you’d see black or whenever you about to past out
It's called Ice Wedging :)
The number of covalent bonds that an atom can make is determined by the no. of electrons needed to form a duplet or octet of electron by each of the atom.
