Answer:
我實際上不知道答案，我只是為了點數而這樣做，哈哈，祝你好運哈哈
Explanation:
我實際上不知道答案，我只是為了點我實際上不知道答案，我只是為了點數而這樣做，哈哈，祝你好運哈哈數而這樣做，哈哈，祝你好運哈哈
Gamma radiation have the most penetrating power. It can penetrate through human body, aluminum and other metals. It can be stopped by lead. Hence, the radioactive waste are stored in lead container for safety purposes. The beta ray has more penetrating power than the alpha but less than gamma. The beta radiations can be stopped by aluminum. The alpha radiations have least penetrating power and it can be stopped by human hands.
Answer:
VH2SO4 = 145.3 mL
Explanation:
Mw BaO2 = 169.33 g/mol
⇒ mol BaO2 = 53.5g * ( mol BaO2 / 169.33 g BaO2) = 0.545 mol BaO2
⇒according to the reaction:
mol BaO2 = mol H2SO4 = 0.545 mol
⇒ V H2SO4 = 0.545 mol H2SO4 * ( L H2SO4 / 3.75 mol H2SO4 )
⇒V H2SO4 = 0.1453 L (145.3 mL)
Step one calculate the moles of each element
that is moles= % composition/molar mass
molar mass of Ca = 40g/mol, S= 32 g/mol , O= 16 g/mol
moles of Ca = 29.4 /40g/mol=0.735 moles, S= 23.5/32 =0.734 moles, O= 47.1/16= 2.94 moles
calculate the mole ratio by dividing each mole with smallest mole that is 0.734
Ca= 0.735/0.734= 1, S= 0.734/0.734 =1, O = 2.94/ 0.734= 4
therefore the emipical formula = CaSO4
Answer:
4) Van der waals forces
Explanation:
Krypton (Kr) belongs to the noble gas group and has fully filled valence orbitals. In the solid phase, Kr exists as a white solid with a face centered cubic structure.
Intermolecular forces of attraction from the strongest to the weakest include:
Ionic > hydrogen bonding > dipole-dipole > london dispersion
Kr is monoatomic and non-polar. When fully filled (stable) valence orbitals of 2 Kr atoms approach each other in close proximity they experience a repulsive force which prevents the formation of strong bonds. Thus, the only force of attraction in Kr is the long range weak Van Der Waals force also known as the london dispersion force.
