27. Some forces require direct contact, while others, like gravity, act at a distance. Which of the following is NOT influenced by gravity?
A. Earth's tides
B. your weight
C. Earth's orbit
D. magnetism

Write the symbol for every chemical element that has atomic number greater than 3 and atomic mass less than 12.0 u.

Balance and in which category does it fit in? single or double displacement or synthesis or decomposition? (a) k2 o → k + o2 (b) na + i2 → nai (c) cu(no3 )2 + naoh → cu(oh)2 + nano3 (d) kclo3 → kcl + o2 (e) ca(no3 )2 + hbr → cabr2 + hno3 (f) sn(oh)2 → sno + h2 o (g) p4 + n2 o → p4 o6 + n2 (h) fe + al2 (so4 )3 → feso4 + al (i) alcl3 + na2 co3 → al2 (co3 )3 + nacl (j) c3 h6 + o2 → co2 + h2 o

The atomic number, or number, is the described as the number of in the nucleus of an chemical element.