Yara is learning about radioactivity. She understands that radioactive isotopes have unstable nuclei. What type of radiation is commonly emitted by radioisotopes?

Which element is placed in period 2?

Which subatomic particle has a negative charge?

Which block contains transition metals?

Tina is studying the properties of halogens. She notes that the color of halogens becomes darker as we move down the group. What is the color of iodine at room temperature?

Ethan is studying the Heisenberg uncertainty principle. He understands that it limits what we can know about an electron. Which two properties are affected by this principle?

How many groups are present in the modern periodic table?

Lara is studying the reactivity of alkali metals with water. She knows that sodium reacts vigorously with water. What product is formed when sodium reacts with water?

Subshells are denoted by:

Ahmed is learning about early atomic models in his chemistry class. His teacher explains that John Dalton proposed the first scientific atomic theory. According to Dalton's model, what did he propose about atoms?