The half life of strontium 90 is 28.8 years
Answer:
the environmental benefits of rain water harvesting
Explanation:
rainwater harvesting can reduce stormwater runoff a property by reducing stormwater runoff rainwater harvesting can reduce is term peak flow volume and velocity in local cricket stream and rivers thereby reducing the potential for stream Bank erosion
Bonds formed between atoms can be classified as ionic and covalent
Ionic bonds are formed between atoms that have a high difference in the electronegativity values.
In contrast, bonds formed between atoms that have a difference in electronegativity lower than the ionic counterparts are polar covalent bonds. If the atoms have very similar electronegativities, they form non-polar covalent bonds.
In H2S, the S atom is bonded to 2 H atoms. The electronegativity of H = 2.2 and S= 2.56. Since the difference is not high the bond formed will be covalent (polar covalent).
Answer:
Frequency = 0.005× 10¹⁷ s⁻¹
E = 0.03 × 10⁻²⁰KJ
Explanation:
Given data:
Wavelength of light = 630.0 nm (630 × 10⁻⁹ m)
Frequency of light = ?
Energy in joule = ?
Solution:
speed of light = wavelength × frequency
Frequency = speed of light / wavelength
Frequency = 3 × 10⁸ m/s / 630 × 10⁻⁹ m
Frequency = 0.005× 10¹⁷ s⁻¹
Energy:
E = h. f
E = 6.63× 10⁻³⁴ Kg. m²/s × 0.005× 10¹⁷ s⁻¹
E = 0.03 × 10⁻¹⁷ j
E = 0.03 × 10⁻¹⁷ j×1 kj /1000 j
E = 0.03 × 10⁻²⁰KJ
