chemistry p.2

Question 1

physical changes

Answer 1

change of form or shape
change of state
dissolving

Question 2

chemical changes

Answer 2

new colour appears
heat/light produced or absorbed
a solid material precipitate
difficult to reverse

Question 3

cations

Answer 3

loses electrons and have a positive net charge

Question 4

anions

Answer 4

gain electrons and have a negative net charge

Question 5

whats the difference between a regular BR diagram for an element or ion

Answer 5

For ions, u need to add the brackets outside the BR diagram and the net charge at the top of the brackets. U also need to remove or add any necessary electrons to stabilize the element.

Question 6

reactivity of metals vs nonmetals in periods

Answer 6

reactivity of metals increases from right to left. Reactivity of nonmetals increases from left to right.

Question 7

reactivity of metals vs nonmetals in groups

Answer 7

reactivity of metals increases from the top to the bottom. Reactivity of nonmetals increases from the bottom to the top.

Question 8

the more shells?

Answer 8

the more prone it is to losing electrons.

Question 9

2 (NH4)2CR2O7

Answer 9

elements-nitrogen-hydrogen-
#of atoms 4 16
chromium-oxygen
4 14

total # of atoms= 4+16+4+14= 38
total # of molecules= 2

Question 10

reactants =

Answer 10

products

Question 11

H2 + O2=

Answer 11

H2O