Answer:A.Preventing convection currents that take heat aloft, in the same way that the glass of a greenhouse stops convection currents and so makes the air in the greenhouse warmer.
Explanation: when ultraviolet solar radiation penetrates into the Earth's atomosphere and heats it,
the conventional radiation is supposed to be radiated back into the atmosphere as heat.however this is prevented from happening due to green house gases,they absorb the radiant heat and retain this heat within the Earth's environment and so behaves like the glass barrier in green houses.these green house gases trap heat within the Earth causing global warming .
There are three types of artificial cloning:
Gene cloning: copies a few segments of DNA or genes.
Reproductive cloning: it copies the whole animal.
Therapeutic cloning: produces embryonic stem cells for experiments aimed at creating tissues to replace injured or diseased tissues.
Answer:
λ = 5.68×10⁻⁷ m
Explanation:
Given data:
Energy of photon = 3.50 ×10⁻¹⁹ J
Wavelength of photon = ?
Solution:
E = hc/λ
h = planck's constant = 6.63×10⁻³⁴ Js
c = 3×10⁸ m/s
Now we will put the values in formula.
3.50 ×10⁻¹⁹ J = 6.63×10⁻³⁴ Js × 3×10⁸ m/s/ λ
λ = 6.63×10⁻³⁴ Js × 3×10⁸ m/s / 3.50 ×10⁻¹⁹ J
λ = 19.89×10⁻²⁶ J.m / 3.50 ×10⁻¹⁹ J
λ = 5.68×10⁻⁷ m
Answer:
Periods
Explanation:
The vertical columns on the periodic table are called groups or families because of their similar chemical behavior. All the members of a family of elements have the same number of valence electrons and similar chemical properties. The horizontal rows on the periodic table are called periods.
Answer:
c. Hfus is always negative.
Explanation:
Because energy is released when fusing solids
