Question

Fill In the blanks :
1) An atom that loses electrons becomes a positively-charged ion called.................
2) A.............is a number that we place in front of a symbol or formula in an equation.
3) .......................is neither created nor destroyed during a chemical reaction. 4) An acid turns blue litmus paper or solution.........................
5) Chemical reactions in which heat is absorbed are called....................​

Answer 1

Answer:

cathode

atomic no.

energy

sulphur

Explanation:

endothermic

Answer 2

Answer:

1-- cations

Atoms that lose electrons acquire a positive charge as a result because they are left with fewer negatively charged electrons to balance the positive charges of the protons in the nucleus. Positively charged ions are called cations. Most metals become cations when they make ionic compounds.

2--

The numbers placed in front of formulas to balance equations are called coefficients, and they multiply all the atoms in a formula. Thus, the symbol “2 NaHCO3” indicates two units of sodium bicarbonate, which contain 2 Na atoms, 2 H atoms, 2 C atoms, and 6 O atoms (2 X 3= 6, the coefficient times the subscript for O)

3--

The Law of Conservation of Mass dates from Antoine Lavoisier's 1789 discovery that mass is neither created nor destroyed in chemical reactions. In other words, the mass of any one element at the beginning of a reaction will equal the mass of that element at the end of the reaction.

4--

Litmus is extracted from lichens. It has a mauve (purple) colour in distilled water. When added to an acidic solution, it turns red and when added to a basic solution, it turns blue. So, it is used to test the acidic or basic nature of solutions.

5--

endothermic: Heat is absorbed by the system from the surroundings. exothermic: Heat is released by the system into the surroundings.