answer:In IR spectroscopy, a KBr pellet is used as a sample holder because it is transparent to infrared radiation and does not interfere with the absorption spectrum of the sample. KBr is an ionic compound with strong ionic bonds, which means that the atoms in the KBr pellet are held together by strong electrostatic forces. These strong bonds prevent the KBr pellet from stretching or bending, which would otherwise interfere with the IR spectrum of the sample. Additionally, KBr is relatively inexpensive and easy to obtain, making it a practical choice for use in IR spectroscopy.

answer:The circumference of a circle is calculated using the formula C = πd, where C is the circumference, π is a mathematical constant approximately equal to 3.14, and d is the diameter of the circle. Given that the diameter of the circle is 12.6 cm, we can substitute this value into the formula: C = πd C = 3.14 * 12.6 C = 39.564 To round this answer to the nearest hundredth, we look at the digit in the thousandths place, which is 6. Since 6 is greater than or equal to 5, we round up the hundredths place by 1. Therefore, the circumference of the circle rounded to the nearest hundredth is 39.58 cm. The answer is 39.58 cm

answer:To calculate the final price, we need to first find the amount of the discount. We can do this by multiplying the original price by the discount percentage: Discount = Original Price × Discount Percentage Discount = 150 × 10% Discount = 15 Next, we need to subtract the discount from the original price to find the final price: Final Price = Original Price - Discount Final Price = 150 - 15 Final Price = 135 Therefore, the final price of Clair's purchase is 135. The final price is 135.

answer:The mass doubles. This can be seen from the equation D=m/v, where D is density, m is mass, and v is volume. If v is doubled and D remains the same, then m must also double to keep the equation true.