Stabileste daca propietatile substantelor din enunturi sunt fizzice sau chimice. a) Apa se descompune in doua subst gazoase , oxigen si hidrogen, cu ajutorul curentului electric. b)Heliul, gazul folosit la umplerea baloanelor, este de 14,45 ori mai usor decar aerul. c)Oxigeul se dizolva partial in apa, fapt dovedit prin existenta vietii subacvactice d)Dioxidul de carbon nu arde si nu intertine arderea, de accea se foloseste la producerea unor stringatoare de incendiu

Why is the bond angle in a water molecule less than the bond angle of methane? a. the central oxygen atom in water has two lone pairs of electrons, whereas the central carbon atom in methane has no lone pairs. b. the central hydrogen atom in water has one lone pair of electrons, whereas the central carbon atom in methane has two lone pairs. c. the central oxygen atom in water has four lone pairs of electrons, whereas the central carbon atom in methane has only one lone pair. d. the central oxygen atom exerts more repulsive force on surrounding atoms than the central carbon atom in methane does. reset next