When do elements absorb energy and enter an excited state?

What are people who study wildfires called

Water is 11.2% by mass hydrogen. How many kilograms of water would contain 5.8 g of hydrogen?

What element is represented by 1s22s22p63s23p64s5

What is the reaction that joins thousands of small, identical molecules to form one very long molecule?

Which of the following make up the nucleus of an atom? A. protons and neutrons B. electrons only C. neutrons only D. protons and electrons

How many of the following elements have 2 unpaired electrons in the ground state? C Te Hf Si A) 1. B) 2. C) 3. D) 4.

Which has a higher frequency, a neutron or electron? Why?

1) Identify the intensive properties of a sample of matter: A. mass B. hardness C. color D. volume E. reflectivity

Suppose you have a buffer containing 0.400 M hydrazine and 0.300 M hydrazinium chloride at equilibrium. Then you add 25.2 g of NaOH to 2.0 L of the buffer. What change in pH is caused by the addition of the base? A) 0.99 B) 0.40 C) 8.71 D) - 0.36

The heart is an example of which level of organization within an organism? O cell organ tissue organ system O O