The three factors determine the chemical properties of an element:
<span><span>The number and arrangement of electrons in an atom
</span><span>The number of valence electrons
</span><span>The number and arrangement of electrons</span></span>
Answer : The pressure of the helium gas is, 1269.2 mmHg
Explanation :
To calculate the pressure of the gas we are using ideal gas equation:
where,
P = Pressure of 
gas = ?
V = Volume of gas = 210. mL = 0.210 L (1 L = 1000 mL)
n = number of moles = 0.0130 mole
R = Gas constant = 
T = Temperature of gas = 
Putting values in above equation, we get:
Conversion used : (1 atm = 760 mmHg)
Thus, the pressure of the helium gas is, 1269.2 mmHg
Answer:
ELEMENTS MIXTURE
Elements are made up of one kind of atoms. Mixtures are made up of two or more kinds of Compounds .
Elements cannot be broken down into simpler substances by any physical or chemical method. The various constituents are seperated by simple physical means
Explanation:
10 valence electron are there
Answer:
Use a scientific calculator
