1 Male cats are more likely to have obstruction of the urethra due to stones because the urethra is longer and narrower in males than in females. 2  This may result in a higher risk of bladder rupture. 3  Also male cats can have abnormalities of the prostate gland that cause obstruction of the urethra.
Abundances of the Elements in the Earth's Crust. Given the abundance of oxygen and silicon in the crust, it should not be surprising that the most abundant minerals in the earth's crust are the silicates. Although the Earth's material must have had the same composition as the Sun originally, the present composition of the Sun is quite different.
10 Most Abundant Elements in the Earth's Crust. Source: CRC Handbook of Chemistry and Physics, 77th Edition