It is true that the iron recommendation for girls exceeds that of boys during adolescence.
During an adolescence, girls and boys require iron for a large growth spurt and the gain of adult phenotypes and biologic rhythms.
In this period of the life, iron recommendation increase in both girls and boys, because of the increase in lean body mass, the expansion of the total blood volume, the increase and start of menstruation at girls.
Iron is essential for oxygen transport, red blood cell creation, cognitive performance and immunological function.
The overall iron requirements for girls are up to twice as boys.
More about adolescence: brainly.com/question/13528489
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The population would decrease, the more predators there are the more food needed for the species .
Answer: 4.18925 kJ heat is needed to convert 25.0 g of solid ethanol at -135 °C to liquid ethanol at -50°C.
Explanation:
Temperature of Solid 
Melting temperature of Solid 
Temperature of liquid 
Specific heats of solid ethanol = 0.97 J/gK
Specific heats of liquid ethanol = 2.3 J/gK
Heat required to melt the the 25 g solid 
at 159 K
= 159 K - 138 K = 21 K
Heat required to melt and raise the temperature of upto 223 K
= 223 K - 159 K = 64 K
Total heat to convert solid ethanol to liquid ethanol at given temperature :
(1kJ=1000J)
Hence, 4.18925 kJ of heat will be required to convert 25.0 g of solid ethanol at -135 °C to liquid ethanol at -50°C.
Answer:
<span>In ionic compounds, <u>Metals</u> lose their valence electrons to form positively charged Cations.
Explanation:
Metals have the ability to loose elctrons readily. For example metals of Group IA and Group IIA readily looses electrons in order to obtain Noble Gas Configuration. On the other hand Non-metals tends to gain electrons and acquire negative charge. While Ions are made when an an element gain or loose electrons. After loosing electrons element get positive charge which is called as Cation while on gaining electron it gets negative charge called as Anion.</span>
Elements have neutral charges such as Na so if X has 72 protons + charges then it must also have 72 electrons with - charges
hope that helps
