24. <span>Valence electrons are most loosely held by the atom and are involved in chemical reactions. Chemical reactions occur when valence electrons are shared between atoms. The number of valence electrons determines how these reactions take place and what kind of bonds they form.
25 </span><span>Sodium has one valence electron and chlorine has seven valence electrons. The Ione valence electron from sodium is lost and is transferred to the chlorine atom. The result is a sodium ion with a charge of 1+ and a chloride ion with a charge of 1-. The oppositely charged ions attract each other and the charges balance to make a compound that is electrically neutral.
26. </span><span>Ionic compounds have high melting points and high boiling points compared to molecular compounds. Ionic compounds that are dissolved in water or melted will conduct electricity. Molecular compounds do not conduct electricity in either case.
27. </span><span>A covalent bond is formed when two atoms share valence electrons. Neither atom loses electrons or takes electrons from the other. No charged particles form. In an ionic bond, one or more electrons are transferred from one atom to another. Atoms that lose electrons become positively charged ions, and atoms that gain electrons become negatively charged ions. These oppositely charged particles then attract each other.
28. </span><span>A metal crystal consists of positively charged metal ions embedded in a "sea" of loosely held valence electrons that can move around easily. Heat travels through materials as the increased motion of the particles in the hotter parts of the material is passed along to the particles in the cooler parts. In a metal, since particles are easily set in motion, heat is easily transferred or conducted. The same is true for the conduction of electricity. Electricity can flow when charged particles, such as electrons, are free to move. Since the electrons in a metal crystal can move freely among the atoms, electricity is easily conducted.</span>
There are approximately 160 grams in 1 mol of Fe2O3 molecules. Therefore, there would be 79/160= 0.49375 mols of Fe2O3 molecules in 79 grams. There are 5 atoms in total for each molecule of Fe2O3, therefore 79/160 * 5 = 79/32 = 2.46875 mols of atoms.
Answer: exothermic
EXPLANATION: any process in which heat energy is released is called an exothermic process. For example burning of wood produces heat, so combustion of wood is an exothermic process.
When chemicals were not mixed they were at room temperature and when we mix them exothermic reaction took place and heat was released which raised the temperature of mixture.
Answer:
I think the answer is C because I know
Answer:
Electrons conducted heat
Explanation:
Iron is a metallic compound. One property of metallic compounds are that they have many loose electrons.
Consider the two rods to be a singular rod, since they touch:
An uncountable number of electrons at one end of the rod are heated, so they gain kinetic energy. Those electrons then collide with other electrons, which energize those as well (although less), which is equal to adding heat. This is a pattern that will flow all the way through the rod.
