An electromagnetic wave has a frequency of 45,000,000 Hz. What is this frequency in scientific notation?
O A. 4,5*10^8 HZ
B. 4.5 * 10^8 HZ
O c. 4.5*10^7 HZ
D. 4.5*10^8 HZ​

City a and city b had two different temperatures on a particular day. on that day, four times the temperature of city a was 8â° c more than 3 times the temperature of city b. the temperature of city a minus twice the temperature of city b was â’3â° c. what was the temperature of city a and city b on that day? city a was 5â° c, and city b was 4â° c. city a was 3â° c, and city b was â’1â° c. city a was 8â° c, and city b was â’3â° c. city a was 5â° c, and city b was â’5â° c.

Use the drop-down menus to answer each question. which runner finished the 100 m race in the least amount of time? which runner stopped running for a few seconds during the race? at what distance did anastasia overtake chloe in the race?

Air can be considered a mixture. which statement does not explain why?