Answer:
Yes.
Explanation:
Substances are made up of matter or matter are made up of tiny molecules or atoms that occur naturally or some are synthetic or man made.
All matter are made up of substances called elements and each elements have its own physical and chemical properties and cannot be broken easily by ordinary chemical reactions.
Of all the 118 elements only 92 occur naturally and 26 are man made or synthetic which are made in the laboratories.
Answer:
The alkaline earth metals are six chemical elements in group 2 of the periodic table. They are beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra).
Explanation:
hope that helps
Answer: -
6.26 grams
Explanation: -
Atomic Mass of sodium Na = 23 gram
Mass of Na = 18 g
Atomic mass of oxygen O = 16 gram
Molar mass of O2 = 16 x 2 = 32 gram
The balanced chemical equation for the reaction is
4 Na + O2 -- > 2 Na 2 O
From the balanced chemical equation, we see
4 Na requires 1 O2
4 x 23 gram of Na requires 32 gram of O2
18 g of Na gives

= 6.26 grams of O2
For the reaction of formation of Na2O, for 18.0 g of Na, 6.26 grams of O2 are needed for reaction.
<h3>The enthalpy of combustion per mole of anthracene : 7064 kj/mol(- sign=exothermic)</h3><h3>Further explanation </h3>
The law of conservation of energy can be applied to heat changes, i.e. the heat received/absorbed is the same as the heat released
Q in = Q out
Heat can be calculated using the formula:
Q = mc∆T
Heat released by anthracene= Heat absorbed by water
Heat absorbed by water =

mol of anthracene (MW=178,23 g/mol)

The enthalpy of combustion per mole of anthracene :

#3 would be 0.0056
#2 would be 9.92
#1 would be 0.011