Class 6 Science Chapter 6: Materials Around Us (Hinglish Notes)

Cheezein aur materials

Chapter ek purane Bharatiya granth, Rasaratnasamuchchaya, se shuru hota hai, jo kehta hai ki crucible, yaani padaarth pighlaane ka bartan, mitti aur lohe se banta hai. School mein Ghulan aur Sheeta apni nayi notebooks aur pen dikhaate hain, aur unki teacher, Madam Vidya, poochhti hain ki roz ki cheezein ek doosre se kaise milti-julti aur alag hain. Ye sab materials se bani hain, jaise kaagaz, lakdi, kapda, kaanch, dhaatu, plastic aur mitti. Jis padaarth se koi cheez banaayi jaaye, use material kehte hain.

Log apne materials bahut pehle se jaante hain. Indian subcontinent ke sabse purane mitti ke bartan, Ganga ke maidaan ke Lahuradewa aur Baluchistan ke Mehrgarh se, 7,000 se 8,000 saal purane hain, aur Harappa kaal (2600 se 1900 BCE) tak kumhaar chaak par mitti ghumaate, bhatti mein pakaate aur rangte the. Paki mitti ko terracotta kehte hain.

Materials chunna aur group karna

Kisi common property se cheezon ko groups mein rakhna classification hai. Kirane waala masaale ek kone mein aur daalein doosre mein rakhta hai, aur rasoi mein ek jaise bartan saath rakhe jaate hain. Kisi cheez ke liye material uski properties aur cheez ke kaam se chunte hain: gilaas mein paani rukna chahiye, isliye wo kaanch, steel, taamba, peetal, terracotta ya plastic ka ban sakta hai, kapde ka nahi. Ek cheez mein kai materials ho sakte hain; pen mein plastic, dhaatu aur syaahi hoti hai. Alag khelon ki gendein alag materials se banti hain taaki unka uchhalna aur pakad khel ke hisaab se sahi ho.

Lustre aur hardness

Chamakdaar satah waale materials lustrous hote hain; ye aam taur par dhaatuein hain, jaise loha, taamba, zinc, aluminium aur sona. Kuch dhaatuein hawa aur nami se apni chamak kho deti hain, isliye chamak taaze kate hisse par sabse saaf dikhti hai. Kaagaz, lakdi, rubber aur jute non-lustrous hain. Par har chamakti cheez dhaatu nahi hoti: polish, ya plastic ya wax ki patli parat, kisi bhi satah ko chamka sakti hai. Jo materials aasaani se dab ya khurach jaayein wo soft hain, aur jo mushkil se, wo hard; par ye properties tulnaatmak hain: rubber sponge se hard par lohe se soft hai. Aur padho materials ki properties mein.

Aar-paar dekhna

Transparent materials, jaise kaanch, paani, hawa aur cellophane, se saaf dikhta hai; translucent materials, jaise frosted glass aur butter paper, se dhundhla dikhta hai; aur opaque materials, jaise lakdi, cardboard aur dhaatuein, se bilkul nahi dikhta. Chhupan-chhupai mein deewar ya ped tumhe poori tarah chhupa lete hain, par frosted glass ke peechhe tum dhundhli aakriti ki tarah dikhte ho. Aur padho transparent, translucent aur opaque mein.

Paani mein materials

Cheeni aur namak paani mein hilaane par gaayab ho jaate hain: wo ghul jaate hain, yaani soluble hain. Chalk powder, ret aur buraada der tak hilaane par bhi nahi ghulte: wo insoluble hain. Liquids mein sirka aur shahad paani mein mil jaate hain par tel alag parat banaata hai; gases mein oxygen paani mein ghulti hai aur paani ke paudhon aur jaanwaron ko zinda rakhti hai. Hamara sharir paani par nirbhar hai kyunki paani bahut saare materials ghol leta hai. Aur padho soluble aur insoluble substances mein.

Mass, volume aur matter

Ek hi star tak paani, ret aur kankad bhare cups ka wazan alag hota hai: bhaari cup mein zyada mass hai. Mass gram (g) aur kilogram (kg) mein naapte hain; kilogram SI unit hai. Seat par rakha bag jagah gherta hai, aur koi cheez jitni jagah gherti hai wo uska volume hai, millilitre (mL) aur litre (L) mein; SI unit cubic metre hai, aur 1 m³ = 1000 L. Number aur unit ke beech space chhodo, jaise 7 kg ya 500 mL.

Jiska mass ho aur jo jagah ghere, wo matter hai. Paani, ret, kankad aur cup sab matter hain, aur hawa bhi. Materials matter ke wo roop hain jinse cheezein banti hain. Ayurveda, Bharat ki ek chikitsa paddhati, saare matter ko 20 gunon se batata hai, das ulte jodon mein, jaise bhaari aur halka, thanda aur garam, aur naram aur sakht. Chapter ke aakhir mein sawaal hai ki plastic ki khoj vardaan hai ya abhishaap.

Har sawaal ka jawab Chapter 6 ke NCERT solutions mein hai.