Find the percentage of mass in each of the element Ca ( HCO3)2 (Ca= 40, H = 1, O = 16, C= 35)​

% Ca = 24.69%

% H = 1.2%

% C = 14.8%

% O = 59.25%

Explanation:

The percentage by mass of each element can be calculated by dividing the mass of each element in the compound by the molar mass of the compound.

Molar mass of Ca(HCO3)2

Where; (Ca= 40, H = 1, O = 16, C= 12)

= 40 + {1 + 12 + 16(3)}2

= 40 + {13 + 48}2

= 40 + {61}2

= 40 + 122

= 162g/mol

- % mass of Ca = 40/162 × 100

= 0.2469 × 100

= 24.69%

- % mass of H = 2/162 × 100

= 0.012 × 100

= 1.2%

- % mass of C = 24/162 × 100

= 0.148 × 100

= 14.8%

- % mass of O = 96/162 × 100

= 0.5925 × 100

= 59.25%

it is to be noted that an alpha particle is an helium nucleus. so it contains 2 protons 2 neutrons and has a mass number of 4. when alpha decay particles are ejected from the nucleus it gets transformed into an atom which has atomic number less than 2 and a mass number less than 4.

an equation that could represent alpha decay is radium 226 decay of alpha particle forms radon 222.

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out of these options:

ability to burn paper

pure sodium reacting violently with water

the boiling point of water

helium does not tend to react with anything

i would say this is a physical property:

helium does not tend to react with anything

why? :

i said helium does not tend to react with anything because well, it reacts to ! but ability to burn paper, pure sodium reacting violently with water, & the boiling point of water are chemical or

physical properties: the properties of a substance that can be observed without changing the chemical makeup of the substance

chemical properties: properties of a substance relating to the chemical nature and reactivity of the substance