Which of the following statements is true about chemical reactions?

endothermic reactions absorb heat and exothermic reactions give off heat
exothermic reactions absorb heat and endothermic reactions give off heat
endothermic and exothermic reactions absorb heat
endothermic and exothermic reactions give off heat

- both b and d.

-since b and d are the closest coastlines then that makes it the most affected.

< 3

1 a

2 d

3 a

4 c

explanation:

a saline water is fed to a reverse osmosis unit at flow rate o rotameter connected to reject (retentate) line reads 8 installed in reject and permeate line reads 15.2 milli siemens/cm and 300 micro siemens/com respectively.

percent abundance for cu-63 can be shown as:

63 x + 65 (1-x) = 62.9296

65 - 62.9296 = 2 x

x = 1.035

thus, percent abundance for cu-63 is 1.035

percent abundance for cu-65 can be shown as:

63 x + 65 (1-x) = 64.9278

65 - 64.9278 = 2 x

x = 0.0361

thus, percent abundance for cu-63 is 0.0361

the mass spectrum of cu-63 showing the intense peak as, this isotope is found in nature more abundantly around 92.38 % in comparison to cu-65 which is found 62.58 % naturally