It makes the bronze stronger and harder than either of the other two medals
Answer:
Explanation:
From the periodic table, the element designated as Sn is tin. Sn is derieved from a latin name of the metal called Stanum
Selenium Se is a group 6 element. It belongs to the same group with oxygen, sulfur and tellurium. This substance has an atomic weight of 78.96g/mol
Oxygen is a group 6 element with an atomic mass of 16. The atomic mass is the number of protons in the nucleus of this atom.
Properties of matter can be broadly classified into two categories:
Physical properties which usually involve a change in the state of matter and Chemical properties which involve a change in the chemical composition of matter.
Now, physical properties can be further classified as:
Extensive: these depend on the amount of the substance, eg: mass, volume
Intensive: these do not depend on the amount of the substance eg: density, color, melting point, boiling point
Here we are given a 5.0 g and 1 cm3 silver cube :
Therefore:
Extensive properties are-
1) Mass of silver = 5.0 g
2) Volume of silver = 1 cm3
Intensive properties are:
1) Density of silver = mass/volume = 5.0 g/ 1 cm3 = 5.0 g/cm3
2) Melting point of silver = 962 C
3) Color = white/gray
Answer:
(i) Bohr; (ii) de Broglie; (iii) Heisenberg (v) Schrödinger
Explanation:
(i) Niels Bohr — 1913 — proposed that electrons travel in fixed orbits with <em>quantized energy levels</em> and that they jump from one energy level to another by absorbing or emitting quanta of light.
(ii) <em>Louis de Broglie</em> — 1924 — proposed the wave nature of electrons and suggested that all matter behaves as both waves and particles (<em>wave-particle duality</em>).
(iii) Werner Heisenberg — 1927 — formulated quantum mechanics in terms of matrices and proposed his famous <em>uncertainty principle</em>.
(v) Erwin Schrödinger — 1926 — applied wave mechanics to the electron in a hydrogen atom, showing that electrons exist in <em>orbitals </em>rather that orbits.
(iv) <em>Ernest Rutherford</em> — 1911 — proposed that atoms have most of their mass in a central nucleus (<em>nuclear atom</em>). Quantum mechanics had not yet been invented.
