Questions asked by Austte

• Back to user's profile
• Is it possible to recognise sodium ions without using flame?
  
• Calculate the mass of the chalk that contains impurities?
  
• The atomic mass of silver found in nature is Ar (Ag) = 107,983. This silver is made of 107Ag and 109Ag Isotopes. Calculate the proportion of mass of 107Ag isotope which is in natural silver atoms?
  
• In which acid can dissolve AgCl?
  
• How many red fish did fisherman catch?
  
• The product of a two-digit natural number and a number consisting of the same digits in the reverse order is 2430. Calculate that two-digit number?
  
• Calculate #f (2)#, knowing that with any #x ≠ 0# the correct equality #f (x) + 3f (1 / x) = x ^ 2# ?
  
• Prove that: #(s-a_1)^2 + (s-a_2)^2 +cdots+ (s-a_n)^2 =a_1^2 +a_2^2+cdots+a_n^2# when #a_1^2 +a_2^2+cdots+a_n^2 = n/{2s}#?
  
• Prove that: #(a+b)/2 = sqrt( a*b)# When #a>=0# and #b>=0# ?
  
• The frog can do a large jump and a small jump. The large jump is 12 cm long and the small jump is 7 cm. How can it get from point A to point B, when among points is the 3cm distance?
  
• The trapezoid diagonal is 6, it divides the trapezoid into two similar triangles. Find the length of the lower base of the trapezoid if the bigger base is 12?
  
• Tom wrote 3 consecutive natural numbers. From these numbers' cube sum he took away the triple product of those numbers and divided by the arithmetic average of those numbers. What number did Tom write?
  
• It is known that the equation #bx^2-(a-3b)x+b=0# has one real root. Prove that the equation #x^2+(a-b)x+(ab-b^2+1)=0# has no real roots.?
  
• What is the area of the triangle ABC?
  
• What is the radius of the circle?
  
• In the box are 30 lottery tickets. 5 of them are happy. 7 tickets are being fetched. In how many cases, there will be 2 happy tickets?
  
• An unknown element #"X"# with oxygen forms a gas compound #"X"_2"O"# whose density at #-120^@"C"# and a pressure of #"320 mmHg"# is #"1.809 g/L"#. What is element #"X"#?
  
• What are the partial pressures of #"NO"_2# and #"Cl"_2# at equilibrium?
  
• #0.5x^2+bx+8# How to choose b so that 6 children will be able to solve different inequalities and get different answers?
  
• Should I write #H_2SO_4# like a catalyst?
  
• When white light goes through the prism, it splits into a spectrum. Why red rays refract less and purple rays most of all?
  
• In III A group element oxide is #25.53#% oxygen. What is the element?
  
• 100 liters of water for softening needed 15.9 grams of #Na_2CO_3#. What was the hardness of water?