How do you know that melting ice is a physical change?

use words to describe what energy is

what type of energy causes a rain puddle to disappear on a sunny day?

a plumber uses a torch to heat a copper pipe in order to bend it. is this an example of a physical change? explain

compare the properties of broken and unbroken glass. explain why breaking glass is a physical change.

7. what temperature is need to just dissolve 50 g of nh4cl in 75 g of water? '

Flourine is found to undergo 10% radioactivity decay in 366 minutes determine its halflife

1)each group 16 element has how many valence electrons? ( )4 ( )6 ( )8 ( )16 2)how many dots appear in the dot structure for calcium ion, ca2+? ( )zero ( )one ( )two ( )eight 3) which of the following atoms forms a cation to obtain an octet of outer shell electrons? ( )magnesium ( )oxygen ( )fluorine ( )helium 4) an al3+ ion contains 13 protons and 10 electrons. ( )true ( )false 5) valence and non-valence electrons are represented in lewis dot structures. ( )true ( )false