Which of the following indicates a chemical change?

Question 7 options:

A. an exploding firecracker

B. a freezing ice cube

C. wood breaking into splinters

D. a wire conducting electricity

4 wings one tail what am i

How many protons z and how many neutrons n are there in a nucleus of the most common isotope of rubidium, 8537rb?

Use Hess's Law to calculate the heat of reaction for the following reaction: A + 3B → 3C + 2D A + 2B → C + D H = - 20 kJ B → 2C + D H = - 45 kJ Question 10 options: +25 kJ -65 kJ -25 kJ +65 kJ

What biome has a warm and wet climate

A pure sample contains only nitrogen and oxygen atoms. If the sample is 30.4% nitrogen, by weight, what is the empirical formula of the molecule?

Pf3cl2 is a nonpolar molecule. based on this information, determine the f-p-f bond angle, the cl-p-cl bond angle, and the f-p-cl bond angle. enter the number of degrees of the f-p-f, cl-p-cl, and f-p-cl bond angles, separated by commas (e. g.

What is the empirical formula of a substance that contains 2.64g of C, 0.444g H and 3.52g of O

How many liters of space will 7.80 moles of methane gas (CH4) occupy at STP

Which is an example of the flow of heat through conduction? Hot air rises to the top of the room A hot-air balloon rises into the sky Heat flows from a hot liquid to a pot handle Heat causes winds to blow from the water to the land

Jin listed some common thermal insulators and conductors in a chart. A 2-column table with 2 rows. The first column labeled Insulators has entries rubber, air. The second column labeled Conductors has entries copper, X.