Physical Properties<span>: </span>Physical properties<span> can be observed or measured without changing the composition of matter. </span>Physical properties<span> are used to observe and describe matter. so physical changes are the change in temperature of the land and the evaporation of water and change humidity of the air. chemical change is the ripening of the orange</span>
Answer:
first of all is that really chemistry
Answer:
Humans have 23 pairs of chromosomes.
A trisomy is a chromosomal condition characterised by an additional chromosome.
A person with a trisomy has 47 chromosomes instead of 46.
Down syndrome, Edward syndrome and Patau syndrome are the most common forms of trisomy.
Explanation:
Answer:
4.907 × 10^-19 J
Explanation:
The energy of the lasers in a Blu-ray player can be calculated by using;
E = hf
Where;
E = Energy of laser (J)
h = Planck's constant (6.626 × 10^-34 J/s)
f = frequency (Hz)
However, the frequency must be known first in order to calculate the energy. The frequency can be calculated using the formula:
f = v/λ
Where:
λ = wavelength (4.05x10−7 m.)
v = speed of light (3 × 10^8m/s)
f = frequency (Hz)
f = 3 × 10^8 ÷ 4.05 x 10^−7
f = 0.7407 × 10^(8 + 7)
f = 0.7407 × 10^15
f = 7.407 × 10^14 Hz
Using E = hf
E = 6.626 × 10^-34 × 7.407 × 10^14
E = 49.07 × 10^(-34 + 14)
E = 49.07 × 10^-20
E = 4.907 × 10^-19 J