The statement that best describes waves is B. Waves cannot propagate without a medium
Answer:
Zinc reacts with dilute sulphuric acid to produce hydrogen gas (H2) and zinc sulphate. This is an example of displacement reaction of a non-metal by a metal. ... ZnSO4 is different in chemical composition and chemical properties than Zn and H2SO4 so it is a chemical change.
Answer:
D. F
Explanation:
Electron affinity is defined as the change in energy (in kJ/mole) of a neutral atom (in the gaseous phase) when an electron is added to the atom to form a negative ion. In other words, the neutral atom's likelihood of gaining an electron.
The electron affinity values of the following elements is given;
Electron Affinity of Hydrogen is 72.8 kJ/mol.
Electron Affinity of Lithium is 59.6 kJ/mol
electron affinity of carbon is 153.9 kJ mol‑1
Electron Affinity of Fluorine is 328 kJ/mol
The electron affinity of neon is 0 kJ mol‑1.
When nonmetals gain electrons, the energy change is usually negative because they give off energy to form an anion (exothermic process); thus, the electron affinity will be negative.
Nonmetals have a higher electron affinity than metals, meaning they are more likely to gain electrons than atoms with a lower electron affinity.
That explains why florine seems to have the highest electron affinity value.
