Answer:
6
Explanation:
To determine the number of neutrons we round 10.8 to 11 and subtract the atomic number (5) and get 6; therefore, boron has 6 neutrons.
Answer:
: The conductivity of electrolyte solutions: (a) 0.1 M NaCl (b) 0.05 M NaCl (c) 0.1 M HgCl2. An electrolyte solution conducts electricity because of the movement of ions in the solution (see above). The larger the concentration of ions, the better the solutions conducts. Weak electrolytes, such as HgCl2, conduct badly because they produce few ions when dissolved (low concentration of ions) and exist mainly in the form of molecules.
Explanation:
Answer:
20 mL
Explanation:
<em>The student should record 20 mL as the correct volume.</em>
The curved surface of a liquid that is usually observed in a buret is referred to as the meniscus. This meniscus is created as a result of the surface tension of the liquid against the walls of the buret. <u>Hence, in order to avoid errors due to parallax, the bottom of the meniscus should be read and not the top.</u>
Therefore, the correct volume that the student should record is 20 mL.
Answer:
5. An element's mass number tells the number of protons in its nucleus.
Atomic
6. Negatively charged particles in an atom are called electrons.
True
7. The cloud model of the atom describes the location of electrons as specific orbits around the nucleus.
Bohr
8. Atoms with the same number of protons but different numbers of neutrons are called isomers.
Isotopes
9. The sum of the protons and neutrons in an atom is called the atomic number.
Mass
10. An object that helps explain ideas about the natural world is called a model.
True
11. Mendeleev arranged his periodic table in order of increasing atomic number.
Mass
12. The rows in the periodic table are called periods.
True
13. Moving across the periodic table from left to right, one finds, in order, metals, then gases, then nonmetals.
Metalloids
14. Another name for a period is a family.
Group
15. On the periodic table, elements in the same column have similar properties.
True
Explanation:
