The diagram shows a model of an atom. The model has four different symbols on it. Each symbol represents a different role for one of the particles within the atom.
Model Atom
w
In this model, which particle determines the reactivity of this atom?
A W
ОВ. Х
O C. Y
O D. Z

Which of the following pairs of elements belong to the same groupa. h and he b. li and bec. c and pb d. ga and ge

Agroup of students is studying convection currents. they fill two identical balloons with the same amount of helium. one balloon is placed in a freezer and the other in an area with warm air. after 10 minutes, the balloons are released from a height of 1 meter. which of the following do the students most likely observe? a. the balloons both rise. the cold balloon is larger than the warm balloon. b. the balloons rise at the same rate. both balloons are the same size. c. the warm balloon expands and rises. the cold balloon shrinks and sinks. d. the cold balloon expands and rises. the warm balloon shrinks and sinks.

98 ! and brainliest plz ! the below reaction can be categorized as more than one type of reaction. which reactions are these, and what are the types of reactions?