Nora is studying the properties of noble gases. She knows that they are generally unreactive due to their stable electron configuration. Which noble gas is used in balloons because of its low density?

Electronegativity is the tendency of an atom to:

Non-metals usually form:

Which statement is true about electrons?

The modern atomic model is based on:

Oliver is studying the thermal stability of hydrogen halides. He knows that HF is the most thermally stable. As we move down the group, the bond strength of H-X:

The smallest particle of an element that retains its properties is:

Who discovered the electron?

The region of high probability of finding an electron is called:

Which of the following is a metalloid?

Which subatomic particle has no charge?

The nucleus of an atom contains:

Electrons revolve around the nucleus in:

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?

Xia is studying the properties of alkali metals. She notes that they are soft and can be cut with a knife. As we move down Group 1, the softness of alkali metals generally:

Ionization energy decreases down a group due to:

Emma is learning about the quantum mechanical model of the atom. Her teacher explains that it is the most accurate model. What is a key feature of the quantum mechanical model?

Fatima is studying the Heisenberg uncertainty principle. She learns that it states that we cannot know both the position and momentum of an electron with complete certainty. This principle applies to which model of the atom?

According to particle theory, matter is made up of:

Subshells are denoted by:

Metals are generally found on which side of the periodic table?

George is comparing atomic sizes of elements. He knows that as we move down a group, the atomic size increases. What is the reason for this trend?

Paula is studying the atomic number of an element. She knows that the atomic number is the number of protons. If an atom has 8 protons, what is the atomic number?

Ibrahim is studying the electron affinity of halogens. He knows that fluorine has a very negative electron affinity, while chlorine has an even more negative one. Which halogen has the most negative electron affinity?

Rachel is studying the adaptability of metals. She knows that metals can be hammered into sheets (malleability) and drawn into wires (ductility). Which of the following is a property of metals?

What is the modern periodic law?

Victor is studying the melting points of elements. He knows that metals generally have high melting points, while non-metals have lower melting points. Which of the following has the highest melting point?

Waleed is learning about the relationship between subatomic particles. He knows that protons and neutrons have almost equal mass. What is the approximate relative mass of a proton?

Vera is studying shells and sub-shells. She learns that the second shell (n=2) has two sub-shells: s and p. How many electrons can the p sub-shell hold?

Ming is studying the density of elements in Group 1. He notes that lithium floats on water, while sodium also floats. As we move down the group, the density of alkali metals generally: