Metals. Titanium is very hard, gold is shiny, and copper is ductile(can be pulled into a wire without breaking). <span />
<span>0.06355391 mol
The balanced equation for the reaction is
Na2B4O7*10H2O + 2 HNO3 = 2 NaNO3 + 4 H3BO3 + 5 H2O
So for each mole of Borax to neutralize, it takes 2 moles of HNO3.
Calculate number of moles of Borax
0.2619 g / 381.372 g/mol = 0.0006867 mol
Moles of HNO3 used = 0.0006867 mol * 2 = 0.0013734 mol
Molarity is defined as moles per liter so divide the number of moles used by the volume in liters. So
0.0013734 / 0.02161 = 0.06355391 mol</span>
Answer:
Power, 
No of bulbs = 78400000
Explanation:
We have,
Water flows over Niagara Falls at the average rate of 2,400,000 kg/s, it mean it is mass per unit time i.e. m/t.
It falls from a height of 50 m
The gravitational potential energy of falling water is given by :
P = mgh
Power is equal to the work done divided by time taken. So,

So,

Let there are n bulbs that could power 15 W LED. It can be calculated by dividing the power by 15. So,

It means that the number of bulbs are 78400000.
Explanation:
2H2 + O2 = 2H2O
2mol. 1mol. 2mol
2mol reacts with 1mol
13mol reacts with x
x=<u>13mol</u><u> </u><u>×</u><u> </u><u>1mol</u>
<u> </u><u> </u><u> </u><u> </u><u> </u><u> </u><u> </u><u> </u><u> </u><u>2mol</u>
x= <u>13mol</u>
<u> </u><u> </u><u> </u><u> </u><u> </u><u> </u>2mol
x= 6.5mol of oxygen
Answer:
An element is a pure substance as well, because if we fill up a balloon with just helium gas ,it will only contain helium atoms