The temperature of a sample of water changes from 10°c to 20°c when the sample absorbs 418 joules of heat. what is the mass of the sample?
(1) 1 g (3) 100 g
(2) 10 g (4) 1000

Astable electron arrangement for an atom is one that does not easily change. how is this arrangement arrived at? a. valence electrons are transferred or shared to create a full outer shell of electrons. b. valence electrons are discarded into space to create a full outer shell of electrons. c. protons (positive charge) pair with valence electrons (negative charge) to create a strong bond. d. outer shells with valence electrons are transferred or shared.

What are the coefficients to balance the following equation? ba+br2=babr2

Can anyone explain 1. review your spectrometry data and use the known elements to identify the star's composition. which unknown elements make up this star? justify your element selections. 2. in parts i and ii of the lab, what happened to the electrons of each element to produce the different colors of light? explain your answers using important terms from the lesson and information provided in the laboratory. 3. stars composed of heavier (more massive) elements are often slightly older than stars made predominantly from hydrogen and helium. based on your data, is the newly discovered star a younger star? explain your answer.